Civil War Union Naval Officer. Born in Ohio, he was a boyhood friend of future General and President Ulysses S. Grant. He entered the United States Navy as a midshipman on July 7, 1836, and was ordered to West Point for three months. While there he was taught by his brother, Jacob Ammen, who would later rise to the rank of Brigadier General in the United States Army. By 1861 Daniel Ammen had risen to the rank of commander with a reputation as a solid and responsible officer. His special interest was in new types of ordnance. On November 7, 1861, he commanded the gunboat "USS Seneca" in the attack on Port Royal, South Carolina, and after the Federal landing personally raised the United States flag over Fort Beauregard. In operations on Florida's St. John's River, he was commended by his commanding officer, Admiral Samuel F. Dupont. In March 1863 he commanded the monitor "USS Patapsco" during the successful attack on Fort McAllister, Georgia, and the next month participated in the unsuccessful attack on Charleston, South Carolina. As commander of the steam sloop "USS Mohican", he took part in the final attacks on Fort Fisher, North Carolina in 1864 to 1865. He demonstrated courage and coolness whether in action or faced with mutinous conduct. In May 1864 he was placed in charge of 220 naval recruits aboard the merchant vessel "SS Ocean Queen". While at sea between New York and Panama, a mutiny occurred, which he suppressed by shooting two of the ringleaders. He was chief of the Bureau of Yards and Docks from May 1, 1869, to October 1, 1871, and chief of the Bureau of Navigation from October 1, 1871, until his retirement, June 4, 1878. He reached the rank of Rear Admiral on December 11, 1877. He devoted much time to work on harbor defenses, and designed the ram "USS Katahdin", also the "Ammen balsa," or life-raft, used in the Navy. In 1872 he was appointed member of a commission to examine and report on the feasibility of constructing a canal through Nicaragua. The commission reported in favor of the Nicaraguan route, which he strongly advocated. In 1879, he was sent as a delegate to a congress in Paris to discuss Isthmian canal questions. He also served on the board for the location of the new Naval Observatory. After his retirement he purchased a farm twelve miles from Washington, at a town named in his honor Ammendale, the seat of the Normal School of the Brothers of the Christian Schools, where through his generosity St. Joseph's church was built. Among his works are "The Atlantic Coast"; "Recollections of Grant"; and "The Old Navy and the New" which was autobiographical. He died at his farm.