Although her US Passport Applications give later years for her date of birth (1857 and 1858), her gravestone inscription in Greenfield Cemetery, Uniondale, New York gives a birth date of October 16, 1850. She and many of her family members are buried there.
From the New York Times, March 11, 1942: Barnum-Kate Vail, daughter of the late Peter Crosby and Sarah Ann Barnum (nee Baldwin) at her residence, 1035 Fifth Avenue, (Manhattan, NYC) on Monday, March 9. Services at the chapel of the Beloved Disciple, 5th Avenue at 80th Street, Wednesday, March 11.
From the Brooklyn Daily Eagle, March 11, 1942: Services for Kate Vail Barnum, 91, active in social circles here for many years and a member of the old Long Island family after whom Baldwin, Long Island is named were held today in the chapel of the Beloved Disciple, Manhattan. Miss Barnum died Monday at her home 1035 Fifth Avenue, Manhattan after a brief illness. For more than a score of years her birthdays were attended by large gatherings of her friends here and in distant parts of the country. She was a skillful bridge player and formerly was active in club circles here. Miss Barnum was a daughter of the late Peter Crosby and Sarah Ann Baldwin Barnum. Her mother was one of the large landholders on Long Island, owning large tracts in the vicinity of Hempstead, Merrick and Bellmore. A niece, Mrs. Joseph Hall and a nephew, Edward B. Willetts survive.
Plot: section 3.