His great-great-great-grandson Cornelius Vanderbilt began the prominence of the family, the fourth of nine children born to a Staten Island family of modest means. Through his paternal great-great grandmother Abigail Southard, he descends from Republic of Salé President Jan Janszoon and his son Anthony Janszoon van Salee. They were among the earliest arrivals to 17th-century New Amsterdam. In a number of documents dating back to this period, Anthony is described as tawny or mulatto, as his mother was of Berber origin from Cartagena in the Kingdom of Murcia. Cornelius Vanderbilt left school at age 11 and went on to build a shipping and railroad empire that, during the 19th century, would make him one of the wealthiest men in the world. Starting with a single boat, he grew his fleet until he was competing with Robert Fulton for dominance of the New York waterways, his energy and eagerness earning him the nickname "Commodore", a United States Navy title for a captain of a small task force. Fulton's company had established a monopoly on trade in and out of New York Harbor. Vanderbilt, based in New Jersey at the time, flouted the law, steaming in and out of the harbor under a flag that read, "New Jersey Must Be Free!" He also hired the attorney Daniel Webster to argue his case before the United States Supreme Court; Vanderbilt won, thereby establishing an early precedent for America's first laws of interstate commerce.