February 29, 1840: John Philip Holland, the “father of the modern submarine,” was born in Ireland. After he immigrated to the United States in 1873, he began working on a submersible ship, and in 1881, he launched the Fenian Ram, a 31-foot-long submersible powered by a 15-horsepower internal combustion engine. It submerged 64 feet beneath New York Harbor. In 1895, his J.P. Holland Torpedo Boat Company received its first contract from the U.S. Navy.

Brandus, Paul. This Day in U.S. Military History (pp. 60-61). Bernan Press. Kindle Edition.