Porter was commissioned a second lieutenant on April 22, 1861 and a first lieutenant on June 7, 1861. During the American Civil War, Porter served in the Union Army, reaching the grade of lieutenant colonel by the end of the war. During the war, he served as Chief of Ordnance in the Army of the Potomac, Department of the Ohio and the Army of the Cumberland. He was distinguished in the Battle of Fort Pulaski, Georgia, at the Battle of Chickamauga, the Battle of the Wilderness and the Second Battle of Ream's Station. On June 26, 1902 or July 8, 1902, Porter received the Medal of Honor for the Battle of Chickamauga as detailed in the citation noted below. In the last year of the war, he served on the staff of Gen. Ulysses S. Grant, later writing a lively memoir of the experience, Campaigning With Grant. From April 4, 1864 to July 25, 1866, Porter was aide-de-camp to General Ulysses S. Grant with the grade of lieutenant colonel in the regular army. On July 17, 1866, President Andrew Johnson nominated Porter for appointment as brevet brigadier general, to rank from March 13, 1866, and the U.S. Senate confirmed the appointment on July 23, 1866. From July 25, 1866 to March 4, 1869, Porter was aide-de-camp to General Ulysses S. Grant with the grade of colonel in the regular army.
Grant administration
From 1869 to 1872, Porter served as President Grant's personal secretary in the White House. At the same time, he held the grade of colonel and an appointment as aide-de-camp to General William T. Sherman. Porter had refused to take a $500,000 vested interest bribe from Jay Gould, a Wall Street financier, in the Black Friday gold market scam. He told Grant about Gould's attempted bribery, thus warning Grant about Gould's intention of cornering the gold market. However, during the Whiskey Ring trials in 1876, Treasury SolicitorBluford Wilson claimed that Porter was involved with the scandal. Porter testified before the committee investigating the scandal, and was never formally charged with wrongdoing. Porter resigned from the U.S. Army on December 31, 1873.
Later life
After resigning from the Army, Porter became vice president of the Pullman Palace Car Company, and later, president of the West Shore Railroad. He was U.S. Ambassador to France from 1897 to 1905, paying for the recovery of the body of John Paul Jones and sending it to the United States for re-burial. He received the Grand Cross of the Legion of Honor from the French government in 1904. In addition to Campaigning with Grant, he also wrote West Point Life. Porter was president of the Union League Club of New York from 1893 to 1897. In that capacity, he was a major force in the construction of Grant's Tomb. He was elected an honorary member of the Pennsylvania Society of the Cincinnati in 1902. He was also a member of the Military Order of the Loyal Legion of the United States, the Sons of the American Revolution and a Hereditary Companion of the Military Order of Foreign Wars by right of his descent from Lieutenant Colonel Andrew Porter who served in the American Revolution. In 1891 he joined the New York Society of the Sons of the American Revolution, where he served as President General from 1892 through 1896. He was assigned national membership number 4069 and state membership number 69. He died in Manhattan, New York and is interred at the Old First Methodist Church Cemetery in West Long Branch, New Jersey.
Personal life
In 1863, Porter was married to Sophie King McHarg, the daughter of John McHarg and Martha Whipple Patch. Together, they were the parents of:
Horace Porter Jr., who died at the age of 23 of typhoid fever.
After a period of suffering, Porter died at New York, New York, May 29, 1921. He was buried in West Long Branch Cemetery, West Long Branch, New Jersey. In his will, he left the Grant Association $10,000 and the flag that flew at General Grant's field headquarters during the Civil War.
