Among Theodore Roosevelt's many lifetime accomplishments, few capture the imagination as easily as his military service as a "Rough Rider" during the Spanish-American War. America had become interested in Cuba's liberation in the 1890s as publications portrayed the evil of Spanish Rule. No one favored Cuban independence more than Roosevelt. As Assistant Secretary of the Navy, he beat the war drum and prepared the Navy for war with Spain. The battleship USS Maine was dispatched to Havana, Cuba. After a few quiet months, anchored in Havana Harbor, the Maine suddenly exploded, killing 262 American sailors. Spain denied blowing up the Maine, but a US Navy investigation concluded that the explosion was caused by a mine. The cause of the explosion remains a mystery, but American journalists and Assistant Secretary Roosevelt, at the time, felt certain that it was a Spanish act of war. Shortly thereafter, war was declared.