On 31 December 2019, China announced the discovery of a cluster of pneumonia cases in Wuhan. The first American case of COVID-19 was reported on January 20, and Health and Human Services Secretary Alex Azar declared a public health emergency on January 31. Restrictions were placed on flights arriving from China, but the initial U.S. response to the COVID-19 pandemic was otherwise slow in terms of preparing the healthcare system, stopping other travel, and testing. The first known American deaths occurred in February and in late February President Donald Trump proposed allocating $2.5 billion to fight the outbreak. Instead, Congress approved $8.3 billion and Trump signed the Coronavirus Preparedness and Response Supplemental Appropriations Act, 2020 on March 6. Trump declared a national emergency on March 13. The government also purchased large quantities of medical equipment, invoking the Defense Production Act of 1950 to assist in those efforts. By mid-April, disaster declarations were made by all states and territories as they all had increasing cases. A second wave of infections began in June, following relaxed restrictions in several states, leading to daily cases surpassing 60,000. By mid-October, a third surge of cases began; there were over 200,000 new daily cases during parts of December 2020 and January 2021.
COVID-19 vaccines became available in December 2020, under emergency use, beginning the national vaccination program, with the first vaccine officially approved by the Food and Drug Administration (FDA) on August 23, 2021. Studies have shown them to be highly protective against severe illness, hospitalization, and death. In comparison with fully vaccinated people, the CDC found that those who were unvaccinated were from 5 to nearly 30 times more likely to become either infected or hospitalized. Nonetheless, there was some vaccine hesitancy for various reasons, although side effects were rare. There were also numerous reports that unvaccinated COVID-19 patients strained the capacity of hospitals throughout the country, forcing many to turn away patients with life-threatening diseases.
A fourth rise in infections began in March 2021 amidst the rise of the Alpha variant, a more easily transmissible variant first detected in the United Kingdom. That was followed by a rise of the Delta variant, an even more infectious mutation first detected in India, leading to increased efforts to ensure safety. The January 2022 emergence of the Omicron variant, which was first discovered in South Africa, led to record highs in hospitalizations and cases in early 2022, with as many as 1.5 million new infections reported in a single day. By the end of 2022, an estimated 77.5% of Americans had had COVID-19 at least once, according to the CDC.
State and local responses to the pandemic during the public health emergency included the requirement to wear a face mask in specified situations (mask mandates), prohibition and cancellation of large-scale gatherings (including festivals and sporting events), stay-at-home orders, and school closures. Disproportionate numbers of cases were observed among Black and Latino populations, as well as elevated levels of vaccine hesitancy, and there was a sharp increase in reported incidents of xenophobia and racism against Asian Americans. Clusters of infections and deaths occurred in many areas. The COVID-19 pandemic also saw the emergence of misinformation and conspiracy theories, and highlighted weaknesses in the U.S. public health system.
In the United States, there have been 103,436,829 confirmed cases of COVID-19 with 1,239,961 confirmed deaths, the most of any country, and the 14th highest per capita worldwide as of March 2023. The COVID-19 pandemic ranks as the deadliest disaster in the country's history. It was the third-leading cause of death in the U.S. in 2020, behind heart disease and cancer. From 2019 to 2020, U.S. life expectancy dropped by three years for Hispanic and Latino Americans, 2.9 years for African Americans, and 1.2 years for White Americans. In 2021, U.S. deaths due to COVID-19 rose, and life expectancy fell.
Timeline
December 2019 to April 2020
In November 2019, COVID-19 infections had first broken out in Wuhan, China. China publicly reported the cluster on December 31, 2019. After China confirmed that the cluster of infections was caused by a novel infectious coronavirus on January 7, 2020, the CDC issued an official health advisory the following day. On January 20, the World Health Organization (WHO) and China both confirmed that human-to-human transmission had occurred. The CDC immediately activated its Emergency operations center (EOC) to respond to the outbreak in China. The first report of a COVID-19 case in the U.S. was publicly reported, though the All of Us study (released in 2021) showed that five states already had cases weeks earlier. After other cases were reported, on January 30, the WHO declared a Public health emergency of international concern (PHEIC) – its highest level of alarm – warning that "all countries should be prepared for containment". The same day, the CDC confirmed the first person-to-person case in the U.S. The next day, the country declared a public health emergency. Although by that date there were only seven known cases in the U.S., the HHS and CDC reported that there was a likelihood of further cases appearing in the country.
The Trump administration evacuated American nationals from Wuhan in January. On February 2, the U.S. enacted travel restrictions to and from China. On February 6, the earliest confirmed American death with COVID-19 (that of a 57-year-old woman) occurred in Santa Clara County, California. The CDC did not report its confirmation until April 21, by which point nine other COVID-19 deaths had occurred in Santa Clara County. The virus had been circulating undetected at least since early January and possibly as early as November.
On February 25, the CDC warned the American public for the first time to prepare for a local outbreak. The next day, New York City saw the sickening of its "patient zero", Manhattan attorney Lawrence Garbuz, then thought to be the first community-acquired case. Another case known as "patient zero" in Los Angeles was a man named Gregg Garfield, who spent 64 days in the Burbank Hospital, on a ventilator for 30 days, with a 1% chance to live. Contracting the virus from a ski trip, Garfield was able to return to the slopes, although with some fingers and toes amputated.
In February, Vice President Mike Pence took over for HHS Secretary Alex Azar as chair of the White House Coronavirus Task Force, with Trump saying, "We are very, very ready for this, for anything, whether it's going to be a breakout of larger proportions, or whether we're at that very low level". In late February Trump proposed allocating $2.5 billion to fight the outbreak, but Congress instead approved $8.3 billion with only Senator Rand Paul and Representatives Andy Biggs and Ken Buck voting against, and Trump signed the bill on March 6.
By March 11, the virus had spread to 110 countries, and the WHO began to refer to COVID-19 as a pandemic. The CDC had already warned that large numbers of people needing hospital care could overload the healthcare system, which would lead to otherwise preventable deaths. Director of the National Institute of Allergy and Infectious Diseases Anthony Fauci said the mortality from COVID-19 was ten times higher than the common flu. By March 12, diagnosed cases of COVID-19 in the U.S. exceeded a thousand. Trump declared a national emergency on March 13. On March 16, the White House advised against any gatherings of more than ten people. Three days later, the United States Department of State advised U.S. citizens to avoid all international travel.
By the middle of March, all fifty states were able to perform tests with a doctor's approval, either from the CDC or from commercial labs. However, the number of available test kits remained limited. As cases began spreading throughout the nation, federal and state agencies began taking urgent steps to prepare for a surge of hospital patients. Among the actions was establishing additional places for patients in case hospitals became overwhelmed.
Throughout March and early April, several state, city, and county governments imposed "stay at home" quarantines on their populations to stem the spread of the virus. By March 26, The New York Times data showed the United States to have the highest number of known cases of any country. By March 27, the country had reported over 100,000 cases. On April 2, at Trump's direction, the Centers for Medicare & Medicaid Services (CMS) and CDC ordered additional preventive guidelines to the long-term care facility industry. On April 11, the U.S. death toll became the highest in the world when the number of deaths reached 20,000, surpassing that of Italy. On April 19, the CMS added new regulations requiring nursing homes to inform residents, their families and representatives, of COVID-19 cases in their facilities. On April 28, the total number of confirmed cases across the country surpassed 1 million.
May to August 2020
By May 27, less than four months after the pandemic reached the U.S., 100,000 Americans had died with COVID-19. State economic reopenings and lack of widespread mask orders resulted in a sharp rise in cases across most of the continental U.S. outside of the Northeast. A study conducted in May indicated that the true number of COVID-19 cases in the United States was much higher than the number of confirmed cases with some locations having 6–24 times higher infections, which was further confirmed by a later population-wide serosurvey.
On July 6, the United States Department of State announced the country's withdrawal from WHO effective July 6, 2021. On July 10, the CDC adopted the Infection Fatality Ratio (IFR), "the number of individuals who die of the disease among all infected individuals (symptomatic and asymptomatic)", as a new metric for disease severity. In July, US PIRG and 150 health professionals sent a letter asking the federal government to "shut it down now, and start over". In July and early August, requests multiplied, with a number of experts asking for lockdowns of "six to eight weeks" that they believed would restore the country by October 1, in time to reopen schools and have an in-person election.
One of many events in the news during this period was the 80th Sturgis Motorcycle Rally in Sturgis, South Dakota, with over 400,000 attendees, and from there, at least 300 people in more than 20 states were infected. The CDC followed up with a report on the associated 51 confirmed primary event-associated cases, 21 secondary cases, and five tertiary cases in the neighboring state of Minnesota, where one attendee died of COVID-19. The U.S. passed five million COVID-19 cases by August 8.
September to December 2020
On September 22, the U.S. passed 200,000 deaths, according to data from Johns Hopkins University. In early October, an unprecedented series of high-profile U.S. political figures and staffers announced they had tested positive for COVID-19. On October 2, Trump announced on Twitter that both he and the First Lady had tested positive for COVID-19 and would immediately quarantine. Trump was given an experimental Regeneron product with two monoclonal antibodies and taken to Walter Reed National Military Medical Center, where he was given remdesivir and dexamethasone.
USA Today studied the aftermath of presidential election campaigning, recognizing that causation was impossible to determine. Among their findings, cases increased 35 percent compared to 14 percent for the state after a Trump rally in Beltrami County, Minnesota. One case was traced to a Joe Biden rally in Duluth, Minnesota.
On November 9, President-elect Biden's transition team announced his COVID-19 Advisory Board. On the same day, the total number of cases had surpassed ten million while the total had risen by over a million in the ten days prior, averaging 102,300 new cases per day. Pfizer also announced that its COVID-19 vaccine may be up to ninety percent effective. In November, the Trump administration reached an agreement with a number of retail outlets, including pharmacies and supermarkets, to make the COVID-19 vaccine free once available.
In spite of recommendations by the government not to travel, more than 2 million people flew on airlines during the Thanksgiving period. On December 8, the U.S. passed 15 million cases, with about one out of every 22 Americans having tested positive since the pandemic began. On December 14, the U.S. passed 300,000 deaths, representing an average of more than 961 deaths per day since the first known death on February 6. More than 50,000 deaths were reported in the past month, with an average of 2,403 daily deaths occurring in the past week.
On December 24, following concerns over a probably more easily transmissible new SARS-CoV-2 variant from the United Kingdom, later called Alpha, the CDC announced testing requirements for American passengers traveling from the UK, to be administered within 72 hours, starting on December 28. On December 29, the U.S. reported the first case of this variant in Colorado. The patient had no travel history, leading the CDC to say, "Given the small fraction of US infections that have been sequenced, the variant could already be in the United States without having been detected".
January to April 2021
On January 1, 2021, the U.S. passed 20 million cases, representing an increase of more than a million over the past week and 10 million in less than two months. On January 6, the CDC announced that it had found at least 52 confirmed cases of the Alpha variant, and it also stressed that there could already be more cases in the country. In the following days, more cases of the variant were reported in other states, leading former CDC director Tom Frieden to express his concerns that the U.S. would soon face "close to a worst-case scenario". It was believed the variant had been present in the U.S. since October.
On January 19, the U.S. passed 400,000 deaths, just five weeks after the country passed 300,000 deaths. On January 22, the U.S. passed 25 million cases, with one of every 13 Americans testing positive for COVID-19. On January 29, a nationwide requirement for use of face masks on public transit and other forms of public transportation was issued by the CDC and the federal Transportation Security Administration, to go into effect on February 1. (Subsequently, extended, the federal mask mandate for public transportation remains in effect in April 2022.)
On February 22, the U.S. passed 500,000 deaths, just five weeks after the country passed 400,000 deaths. By March 5, more than 2,750 cases of COVID-19 variants were detected in 47 states; Washington, D.C.; and Puerto Rico. In the first prime time address of his presidency, on March 11, Biden announced his plan to push states to make vaccines available to all adults by May 1, with the aim of making small gatherings possible by July 4. On March 24, the U.S. passed 30 million cases, just as a number of states began to expand the eligibility age for COVID-19 vaccines. Experts began warning against public relaxation of COVID-19 mitigation measures as vaccines continue to be administered, with CDC director Rochelle Walensky, warning of a new rise in cases.
By April 7, the Alpha variant had become the dominant COVID-19 strain in the U.S. On April 12, the U.S. reported its first cases of a new "double mutant" SARS-CoV-2 variant from India, later called Delta, in California. By April 25, the country's seven-day average of new infections was reported to be decreasing, but concerns were raised about drops in vaccine demand in certain parts of the U.S., which were attributed to vaccine hesitancy. On April 29, the CDC estimated that roughly 35% of the U.S. population had been infected with the virus as of March 2021, about four times higher than the official reported numbers.