December 7, 1941. “A date,” President Franklin D. Roosevelt told the nation, “which will live in infamy.” The surprise attack by the Japanese on Pearl Harbor began at 7:55 a.m. Hawaii time under a clear sky — perfect conditions for the swarms of Japanese fighter pilots to drop their bombs.

The images from that day are apocalyptic. Battleships obliterated, planes destroyed. Smoke. Flames. The next day, as the images of the carnage that killed 2,403 American men, women and children spread throughout the world, Roosevelt declared war on Japan. Not long after that, Italy and Germany declared war on the U.S.

The world was at war, and America was now in it.

Read more about World War II:

This fighter pilot flew the last mission over Japan in WWII. Then he learned to love his enemy.

Brothers in arms: The secrets and service of a World War II family

The savage fight for Guadalcanal: Jungle, crocodiles and snipers during World War II

‘We knew the ship was doomed’: USS Indianapolis survivor recalls four days in shark-filled sea

Unsealed 75 years after the Battle of Midway: New details of an alarming World War II press leak

Dunkirk: No movie could fully capture one of the great dramas of World War II

Hitler refused to use sarin during World War II. The mystery is why.

D-Day’s hero: The man who built the boats that won World War II