In 1900, 1901, and 1904, Cummings was elected mayor of Stamford. His two tenures as mayor were served from 1900–1902 and again from 1904–1906. At the time of his first election, he began a quarter-century of service as a committeeman from Connecticut with the national Democratic party. As mayor, he helped construct and improve streets and sewers, reorganized the police and fire departments, and secured a shorefront park that later was named for him.
