William Emlen Roosevelt was a prominent New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 banker who held a wide range of positions in numerous organizations and was a cousin of United States President Theodore Roosevelt

Theodore Roosevelt

Theodore "Teddy" Roosevelt was the 26th President of the United States . He is noted for his exuberant personality, range of interests and achievements, and his leadership of the Progressive Movement, as well as his "cowboy" persona and robust masculinity...

. He was president of Roosevelt & Son

Roosevelt & Son

Roosevelt & Son was an investment banking firm connected with the Roosevelt Family for nearly two centuries. The firm was among the oldest banking houses on Wall Street.Many of the male members of the Roosevelt family worked for the firm in some capacity....

, the banking firm founded by his father James Alfred Roosevelt

James A. Roosevelt

James Alfred Roosevelt was an American merchant, a member of the Roosevelt family, and an uncle of United States President Theodore Roosevelt. He became a member of his father Cornelius Roosevelt's mercantile firm at the age of twenty, and eventually succeeded him as its head...

. He was director of the Chemical Bank of New York, the Gallatin National Bank, and the Astor National Bank, and later sat on the boards of the Grand Hanover and the Bank of New York

Bank of New York

The Bank of New York was a global financial services company established in 1784 by the American Founding Father Alexander Hamilton. It existed until its merger with the Mellon Financial Corporation on July 2, 2007...

. He was president of Roosevelt Hospital, founded by his distant cousin James H. Roosevelt

James H. Roosevelt

James Henry Roosevelt was an American philanthropist who, by bequest, founded Roosevelt Hospital in New York City. He was born in New York to Catherine and James Christopher Roosevelt, a grandson of Jacobus Roosevelt, the founder of the Hyde Park branch of the Roosevelt family. James H...

. He was an officer of the National Guard for 16 years, major and quartermaster of the First Brigade. Roosevelt became involved in telecommunications companies, formed the Mexican Telegraph Company and Central and South American Telegraph Company, and was eventually director of the International Telephone and Telegraph Company. He also owned the James Alfred Roosevelt Estate

James Alfred Roosevelt Estate

James Alfred Roosevelt Estate, also known as Yellowbanks, is a historic estate located at Cove Neck in Nassau County, New York. It is located several hundred feet west of Sagamore Hill, home of President Theodore Roosevelt. It was designed by noted architect Bruce Price in 1881 as a summer home...

 at Cove Neck

Cove Neck, New York

The Village of Cove Neck is a village located within the town of Oyster Bay in Nassau County, New York, United States. The population was 286 at the 2010 census.-History:...

 in Nassau County, New York

Nassau County, New York

Nassau County is a suburban county on Long Island, east of New York City in the U.S. state of New York, within the New York Metropolitan Area. As of the 2010 census, the population was 1,339,532...

.

Theodore Roosevelt and he had a very close relationship as cousins. Emlen was not interested in politics other than to support his cousin's bids for public office, and Theodore, busy with conservation advocacy, had little time to attend to financial matters. Thus, "Cousin Emlen" was Theodore's financial adviser before, during and after his presidency.