Given the question: Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Casco-class monitor -  The Casco-class monitor was a unique class of light draft monitor built on behalf of the United States Navy for the Mississippi theatre during the American Civil War. The largest and most ambitious ironclad program of the war the project was dogged by delays caused by bureaucratic meddling. Twenty ships of the class were eventually built at great expense but proved so unseaworthy when trialed that they were quickly sidelined causing a public scandal.
The answer is:
Mean Of Transportation