A native of West Hickory, Pennsylvania, Caligiuri was one of many major leaguers who saw their baseball careers interrupted by a stint with the United States Armed Forces during World War II.

A late-season 1941 call-up from Wilmington of the Interstate League, he entered the baseball record books while starting the last game of the season against the Boston Red Sox at Shibe Park.

Over parts of two seasons, Caligiuri posted a 2–5 record with a 4.52 ERA in 18 appearances, including seven starts, giving up 49 runs (nine unearned) on 90 hits and 32 walks while striking out 27 in 79+2⁄3 innings of work.

[4] Caligiuri was recognized as the oldest living major league ballplayer until his death, with Tom Jordan succeeding him.

Caligiuri was the last surviving retired MLB player who made his debut in the majors prior to the Pearl Harbor attack, which led to the United States' involvement in World War II.