The nation's COVID-19 death toll surpassed 600,000 June 15, according to data from Baltimore-based Johns Hopkins University.
The U.S. had reported 600,292 deaths as of June 16 at 8:45 a.m. CDT.
The milestone comes more than 15 months after the nation confirmed its first novel coronavirus death, NPR reported. It took six months for deaths to double, after hitting 300,000 on Dec. 14, 2020.
And while it took about a month to go from 400,000 to 500,000 deaths, it's taken nearly four times as long to hit the 600,000 mark, according to NPR, which cited the vaccine rollout as the main reason for a slowdown.
The U.S. has reported the most COVID-19 deaths in the world, followed by Brazil, India and Mexico.
Globally, more than 3.8 million people have died from COVID-19, Johns Hopkins data shows, though research suggests this figure is likely an undercount.