William Backhouse Astor Jr. (July 12, 1829 – April 25, 1892) was an American businessman, racehorse owner/breeder, and yachtsman who was a member of the prominent Astor family. His elder brother, financier and philanthropist John Jacob Astor III, became head of the British line of Astors in England. William Jr. was head of the American line of Astors, while his wife, Caroline Schermerhorn, served as the leader of New York society's "Four Hundred" during the Gilded Age. Early years William Backhouse Astor Jr. was born on July 12, 1829, in New York City, New York. He was the middle son of real estate businessman William Backhouse Astor Sr. (1792–1875) and Margaret Rebecca (née Armstrong) Astor (1800–1872). His siblings included elder brother John Jacob Astor III, who married Charlotte Augusta Gibbes; Emily Astor, who married Samuel Cutler Ward; Laura Eugenia Astor, who married Franklin Hughes Delano; Mary Alida Astor, who married John Carey; Henry Astor, who married Malvina Dinehart; and Sarah Astor, who died in infancy. Astor's paternal grandparents were fur-trader John Jacob Astor and Sarah Cox (née Todd) Astor. His maternal grandparents were U.S. Senator John Armstrong Jr. and Alida (née Livingston) Armstrong of the Livingston family. A well-liked man, Astor graduated from Columbia College in 1849. He was a member of Columbia's Philolexian Society. Subsequent activity He supported the abolition of slavery before the American Civil War, and during the war, he personally bore the cost to equip an entire Union Army regiment. Unlike his business-oriented father, William Jr. did not aggressively pursue an expansion of his inherited fortune. Instead, he preferred life aboard the Ambassadress, at that time the biggest private yacht in the world, or horseback riding at Ferncliff, the large estate he had built on the Hudson River. Astor's horse "Vagrant" won the 1876 running of the Kentucky Derby. Florida involvement William Jr. often spent winters aboard his yacht in Jacksonville, Florida, and he was responsible for the construction of a number of prominent buildings in the city. He and sixteen other businessmen founded the Florida Yacht Club in Jacksonville in 1876, although he was the only person in Florida to actually own a yacht. The club is now the oldest social club in Jacksonville and one of the oldest yacht clubs in the United States. Liking the area, in 1874, he purchased a land tract of around 80,000 acres (320 km2) along the St. Johns