The oldest section of the Leffingwell House, on Washington Street in Norwich, dates to 1675 and was built by Steven Backus. Sometime later, the house was sold by Backus to Ensign Thomas Leffingwell, son of Lt. Thomas Leffingwell, who had given assistance to the Mohegan Chief Uncas in 1645, when he brought supplies at time when Uncas was under siege by the Narragansett. Leffingwell converted the building for use as a tavern in 1701, adding more rooms. The house is now named for his descendant, Christopher Leffingwell, who later inherited the tavern. He was a merchant and entrepreneur, who eventually built several mills. During the Revolutionary War, Leffingwell was a deputy commissary to the Continental Army and George Washington occasionally stayed at the Leffingwell Inn. In 1957, the house was moved to its present location when a connector was built linking Washington and Town Streets. Today, the Leffingwell House Museum is open to the public and operated by the Society of the Founders of Norwich.