 He was a member of the New York State Assembly (New York Co., 6th D.) in 1849; and of the New York State Senate (5th D.) from 1850 to 1853, sitting in the 73rd, 74th, 75th and 76th New York State Legislatures.In 1861, along with Erastus Corning and Thurlow Weed, Beekman was appointed by a meeting of conservative men in New York to go to Washington and urge President James Buchanan to relieve Fort Sumter.He was vice-president of the New York Hospital, president of the woman's hospital, and a director of the New York dispensary.