NASA

The first living organism sent to space from the U.S. was a chimpanzee called Ham.

An excerpt from the article 29 facts about NASA
Ham, aboard the Mercury Redstone rocket, blasted off on January 31, 1961. “Ham the Astrochimp” was brought back to Earth safely, despite minor technical problems, suffering only mild fatigue and dehydration. Ham was luckier than memorable Laika—a stray mongrel that was sent by the Soviets aboard the Sputnik 2 in 1957, with no intention of bringing her back. She died of suffocation or overheating.