A Timeline seems appropriate:
Dec 10th - One of the earliest known coronavirus patients, starts feeling ill
Dec. 16 - He is admitted to Wuhan Central Hospital with infection in both lungs but resistant to anti-flu drugs. Diagnosis was probably Fever of Unknown Origin and Viral Pneumonia
Dec 30 - Wuhan doctor Li Wenliang also shares information on WeChat about the new SARS-like virus. He is called in for questioning shortly afterward. Authorities have been suppressing physicians' warnings and any notifications.
Dec 31 - China tells the World Health Organization’s China office about the cases of an unknown illness.
Jan. 13: First coronavirus case reported in Thailand, the first known case outside China.
Jan. 14: WHO announces Chinese authorities have seen "no clear evidence of human-to-human transmission of the novel coronavirus."
Jan. 15: The patient who becomes the first confirmed U.S. case leaves Wuhan and arrives in the U.S., carrying the coronavirus.
Jan. 20: The first case announced in South Korea.
Jan. 21: The U.S. Centers for Disease Control and Prevention confirms the first coronavirus case in the United States. Washington State reported the first case of the new coronavirus in the United States in a man who had returned from Wuhan, China.
Jan. 23: Wuhan and three other cities are put on lockdown. Right around this time, approximately 5 million people leave the city without being screened for the illness.
Jan. 24–30: China celebrates the Lunar New Year holiday. Hundreds of millions of people are in transit around the country as they visit relatives.
Jan. 24: China extends the lockdown to cover 36 million people and starts to rapidly build a new hospital in Wuhan. From this point, very strict measures continue to be implemented around the country for the rest of the epidemic.
Jan 30: The first instance of a person transmitting COVID-19 to another person while in the United States was reported in Chicago. A woman in her 60s contracted the virus while caring for her father in China, passing it to her husband when she returned home.
January 31 - A WHO situation report listing 9,826 confirmed cases globally, the World Health Organization declared COVID-19 “a public health emergency of international concern.”
February 26: CDC confirmed a case in California with no reported travel connection to China or exposure to another person with COVID-19.
This marked the first possible instance of community spread—the spread of an illness with an unknown source of infection.
Feb 24 - a right wing pundit says “The coronavirus is the common cold, folks.” and promotes a conspiracy theory "It looks like the coronavirus is being weaponized as yet another element to bring down Donald Trump,"
Feb 27 - POTUS says the outbreak would be temporary: “It’s going to disappear. One day it’s like a miracle—it will disappear.” Anthony Fauci, warned days later that he was concerned that “as the next week or two or three go by, we’re going to see a lot more community-related cases.”
February 29 - CDC announced a 54-year-old man from Washington State was the first person in the U.S. to die of COVID-19-related illness. Since then, 471 total deaths have occurred in the U.S.
March 9 - with the number of its cases surpassing 6,000, Italy imposed a nationwide lockdown.
March 11 - after confirming over 118,000 cases in 114 countries, WHO elevated the status to a pandemic
March 16 - Germany closed its borders to travelers without a valid reason to enter the country.
March 17-19 - California closed all schools, and ordered 40 million Californians to stay at home. Within that time frame or earlier, most other states declared states-of-emergency, closed schools and areas of public gathering and ordered non-essential workers to work at home and others to stay at home except for essential trips.
March 19 - The U.S. announces it will close its borders to unnecessary travel with both Mexico and Canada, effective March 21.
March 23- The CDC estimates that, in a worst-case scenario, 200,000 to 1.7 million Americans could die from COVID-19. Other estimates place the number of possible deaths at 1.1 million to 1.2 million. POTUS says: "Certainly, this is going to be bad." and "If it were up to the doctors, they may say let's keep it shut down -- let's shut down the entire world."
March 24 - Secretary of Defense Mark Esper and Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, noted that there was a roughly three-month period between when the virus first appeared to when it started to taper off.
“You’re looking at somewhere around 90 days based on some of the other countries,” Milley said at the town hall. “That may or may not apply to the United States. We’ll see. If it does apply, you’re looking at probably late May, June — something in that range — maybe could be as late as July.”
March 25 - CDC reported 44,183 cases of COVID-19—both confirmed and presumptive—across the U.S. Coronavirus cases in Africa pass 2,400 amid fears for health services in countries. WHO says numbers are likely higher. S. Africa locks down its borders. Rwanda, Kenya and the Democratic Republic of the Congo (DRC) have all imposed curfews and lockdowns in recent days. The Congo has half a million refugees and five million internally displaced people (IDPs) - the largest IDP population in Africa.
So, it's been less than four months since China notified the WHO of a novel coronavirus, one month since the CDC announced community spread was documented. Two months after locking down their country, China is seeing a decrease in mortality rates at the time the U.S. as a nation is closing its borders and two weeks after most states have limited non-essential travel outside the home, closed schools and restricted public gatherings.