 Claghorn became the first paid secretary-treasurer of the Association of Collegiate Alumnae, the predecessor organization to the American Association of University Women, in 1898.She worked briefly for the US Industrial Commission, the "Economic Year Book", and the US Census Office before joining the New York Tenement House Department as assistant registrar in 1902; she was promoted to registrar in 1906.Her $3000 salary made her the highest-paid female civil servant in New York.