Like his father, Sanders was involved in the fur trade. He became a wealthy merchant and an important landowner. His second marriage to Elizabeth Schuyler, the heiress of one of the oldest families in the region, enabled him to rise in the high society of Albany. In 1750, Sanders even became mayor of the city.
Between 1713 and 1744, Sanders travelled to New France to expand his business relationships. He didn't hesitate to encourage smuggling with Montreal. Thanks to this clandestine trade, Sanders got high quality furs that he could resell at a high price on the European markets.