Jasper Yeates, born in Philadelphia, was once the most prominent lawyer in Lancaster County and served more than 20 years as a state Supreme Court justice. He earned a bachelor’s degree from the College of Philadelphia in 1761, and shortly thereafter went on to study law. After his admission to the Pennsylvania Bar in 1765, Yeates started his law practice in Lancaster.
In addition to his legal duties, Yeates served as captain in the Lancaster militia and played a vital role with the organization and equipping of the militia. His militia duties were interrupted when the Continental Congress appointed Yeates to a Commission of Indian Affairs to negotiate a treaty with the Lenape (Delaware) Indians at Fort Pitt. The Commission’s efforts resulted in the Treaty of Fort Pitt in 1778, which gave American soldiers the right to travel through Delaware territory. In 1787, Yeates served as a delegate to the Pennsylvania State Convention that ratified the United States Constitution.
The low point in Yeates’s legal career came in 1803, when he, Chief Justice Edward Shippen, and Thomas Smith were impeached by the Pennsylvania House of Representatives for charging a man named Thomas Passmore with contempt of court. Yeates and his colleagues were acquitted by the Senate in 1805, and Yeates continued to serve as a state Supreme Court justice until his death in 1817.
HSP's collection of the papers of Jasper Yeates (#740) consists of his notes on trials, evidence, arguments, depositions, and judicial opinions rendered in numerous legal cases. It also contains correspondence and some papers concerning the business affairs of his father, John Yeates.