 Although he shared interests in both philanthropy and military affairs with his father, they eventually had a falling out while Johnston served as a State Assemblyman, and was bitterly opposed by his father in a vote on the 1889 World's Fair Bill. The feud became so heated that while Johnston was Mayor of Tivoli, his father, who owned the building where the town government met, barred his son from entering the building. The village government was forced to move to another building and remained there until 1894, when they finally returned to de Peyster's building. Another incident occurred and was reported in the press when Johnston's mother fell ill, and he visited her at the de Peyster family home and was violently assaulted by his father. The father went so far as to run against his son for Mayor of Tivoli in 1900, but was defeated in the general election. He died in 1903, predeceasing his father as did all of his siblings.
