After the war he settled in
Carlisle, Pennsylvania, and opened a grocery store. He became a member of the
Society of the Cincinnati. Military service again beckoned, and in August 1784 he was commissioned a captain in the
United States Army to serve on the
Ohio Valley frontier in the
First American Regiment under Lieutenant Colonel
Josiah Harmar. In 1789 he was promoted to major by President George Washington. That year he commanded the military escort to
Native Americans, including Chief
Cornplanter, at the
Treaty of Fort Harmar near
Marietta, Ohio. While stationed at
Fort Harmar, Ziegler married Lucy Anne Sheffield on February 22, 1789. Sheffield was a native of Rhode Island, and had come to Marietta with her widowed mother, who was a shareholder in the
Ohio Company. The Zieglers did not have any children. In 1790 Ziegler was a part of
Harmar's campaign against the
Native American confederacy in Ohio, which ended in defeat and retreat to
Fort Washington. Ziegler was a witness at Harmar's court of inquiry: he supported his commander and blamed the debacle on undisciplined
militia, inadequate supplies, and poor
logistics. Commissioned a major in the
First American Regiment on October 22, 1790, the next year Ziegler served as second-in-command under Major
Jean François Hamtramck, and defending the baggage train for General
Arthur St. Clair in another expedition into the Northwest Territory. St. Clair met with even more disastrous results than Harmar at
St. Clair's Defeat. Ziegler performed well, covering the retreat of the fleeing Americans. Ziegler was placed in command of the western forces when St. Clair was recalled for a court of inquiry. Once again Ziegler was called to testify, and again he supported his commander. Disturbed by disputes and jealousy in the officer corps, he resigned from the army on March 5, 1792. ==Cincinnati==