A Yale graduate, Washburn parlayed early business success in furniture manufacture into banking and railroads, based in the Connecticut River valley town of Greenfield. He was a major proponent of railroads in northern and western Massachusetts, sitting on the board of the Connecticut River Railroad for many years, and playing an oversight role in the construction of the Hoosac Tunnel. He has been described as a latter-day "Connecticut River God" because of his role as a leading regional businessman and politician.