The Navy League of the United States was founded in 1902 with the encouragement of President Theodore Roosevelt. No president before him had shown such enthusiastic interest in the Navy, or such firm grasp of its functions and use in foreign affairs. During his first administration, ten new battleships and 21 smaller craft were authorized.
It was at this time that a number of prominent New Yorkers, interested in maintaining American defense against aggression, met on November 20, 1902, at the New York Yacht Club to form “a society to insure the United States against the possibility of being invaded.” The outgrowth of this meeting was the Navy League of the United States.
As the organization grew, support spread from the Navy to include all sea services, adding the Marine Corps, Coast Guard and U.S.-flag Merchant Marine.
https://www.nynavyleague.org/mission