On this date, March 9,1862, the historic Civil War battle took place between the Confederate iron-plated ship Merrimac, which had just destroyed two Union boats, and the Union's ironclad vessel, the Monitor, designed by Swedish Immigrant John Ericsson. After 4 hours of bombardment, with cannon balls deflecting off their decks, the Confederate ship was crippled and withdrew to Virginia. Naval warfare was forever changed that day. When John Ericsson was offered payment for designing the Monitor, he replied: "Nothing could induce me to accept any remuneration. ... [It is] my contribution to the glorious ... triumph ... which freed 4,000,000 bondsmen."