When was the last actually declared war by the congress and not the president

The last formally declared war by the United States Congress was during World War II, specifically against Japan on December 8, 1941, following the attack on Pearl Harbor. This was soon followed by declarations of war against Germany and Italy on December 11, 1941, after those nations declared war on the United States. Since then, the U.S. has engaged in various military conflicts, but these were not preceded by official declarations of war from Congress.