Joseph Gilman was an early jurist and political leader in the Northwest Territory in the years after the American Revolution.
Gilman was born in 1738 and had been major supplier of clothing and supplies to the military in his home state of New Hampshire during the American Revolution. At the end of the war, the collapse of the currency and inability of people to pay their debts caused Gilman to lose much of his own property as well. He decided to come to the Ohio country with his wife and young son and make a fresh start. He arrived at Marietta in 1789.
Arthur St. Clair, the Governor of the Northwest Territory, appointed Joseph Gilman to be a justice of the Court of Common Pleas on November 1, 1795. In 1798, Gilman, Winthrop Sargent, and Return Jonathan Meigs, Jr., served as a sort of legislature for the Northwest Territory and adopted eleven laws. These laws were in addition to thirty-seven laws adopted for the Northwest Territory during the summer of 1795. These original laws were known as Maxwell's Code and were the original civil and criminal code for the Northwest Territory. All laws created by the judges were supposed to come from the legal codes from the original thirteen states at the time of the adoption of the Constitution. However, Gilman, Sargent, and Meigs adopted four from Kentucky. Kentucky did not become part of the United States until 1792, four years after the Constitution went into effect. The judges adopted these laws from Kentucky because conditions in that frontier state were very similar to the problems that the residents of the Northwest Territory were facing as well. Most of the Kentucky laws dealt with criminal activities, land ownership, and horse breeding.
Joseph Gilman died in 1806 and was buried in Marietta, Ohio.