Sailly was born and educated in Lorraine, France, where he was involved in the iron manufacturing business. He immigrated to Philadelphia, Pennsylvania in 1783, purchased land from Zephaniah Platt, and settled in what is now Plattsburgh, New York. He was active in the lumber business, owned several stores, and was a successful fur trader and potash manufacturer. As a result of their shared interest in the fur business, Sailly formed a longstanding friendship with John Jacob Astor.
From 1788 to 1796 Sailly was an associate justice of the Court of Common Pleas. He was Plattsburgh's commissioner of highways and school commissioner in 1797 and 1798, and town supervisor in 1799 and 1800.
Sailly was not a candidate for renomination in 1806. He was appointed U.S. Collector of Customs in Plattsburgh, and served from 1807 until his death.
During the War of 1812 Sailly was appointed keeper of the public stores, a position that gave him responsibility for all government warehouses in upstate New York. in addition, he provided U.S. commanders, including James Wilkinson, intelligence about the Champlain Valley and British troop activities in New York and southern Canada.
Death and burial
He died in Plattsburgh on March 16, 1826. Sailly was buried at Plattsburgh's Riverside Cemetery.
Family
Sailly was married twice. His first wife, Maria Louise Eleonore Caillat, died in 1786. In 1789 he married Marianne Adelaide Grielle, who died in 1830.
Legacy
Sailly was the subject of a biographical work, 1919's Peter Sailly, Plattsburgh and Champlain Valley Pioneer (1754–1826): Extracts from his Diary and Letters, by George S. Bixby.
