He was the president of the American Museum of Natural History and was known as a leading patron of scientific research and an eminent art collector, particularly towards his support for Frederic Edwin Church.

He was descended from Edward Jessup of the Stamford, New Haven Colony, an early settler in Middleburg, Long Island, now Elmhurst, Queens.

Jesup was one of the organizers of the United States Christian Commission during the Civil War, which helped provide care for wounded soldiers.

He donated the funds for construction of the Society's DeWitt (his father-in-law) Memorial Church in Rivington Street on the Lower East Side, a center of immigrant settlement.

Jesup contributed funds and worked personally to better social conditions in New York, in a period when the city was struggling to aid many poor immigrants from rural areas of southern and eastern Europe, including the Russian Empire.

His contributions to Tuskegee Institute enabled George Washington Carver to develop a mobile educational station that he took to farmers.

In 1881, he was appointed president of the American Museum of Natural History, in New York City, to which he gave large sums in his lifetime and bequeathed $1,000,000.

In response, in 1890, as president of the New York State Forestry Association, Jesup's group was one of many to propose new bills whose purpose was to create an Adirondack park.

[10] Jesup died on January 22, 1908, aged 77, at 107 Madison Avenue, his home in New York City and was buried in Green-Wood Cemetery in Brooklyn.