He became a lawyer in 1748 and began his practice in New York City. In 1752, he founded a weekly journal, the "Independent Reflector", along with fellow Presbyterian lawyers William Smith, Jr., the son of his law teacher, and John Morin Scott. The three were called by contemporaries "The Triumvirate". The "Reflector" was New York's first serial non-newspaper publication and the only one being published in British North America at the time. It was used as a platform by the political upstate Presbyterian landed "country faction" led by Livingston for challenging the powerful downstate Anglican and Dutch Reformed merchant or "popular faction" led by chief justice James De Lancey. Most notably the Triumvirate attacked the founding of King's College as a conspiracy by Anglicans to install a bishop in America, including his former tutor now Rev. Henry Barclay Rector of Trinity Church and his former law teacher James Alexander.