Hugh David Vail was born on April 12, 1818, in Plainfield, New Jersey to Nathan Vail and Anna Webster. He married Miriam L. Vail, his third cousin, on May 4, 1871. Together they had two children, Hugh and Edward.
Vail attended Westtown School, and later returned as a teacher of mathematics after working in a drygoods store in New York City. During his career there he provoked several changes in teaching methods and gained valuable experience which would help him later in his position at Haverford College.
At Haverford, Vail taught for seven years as a professor of mathematics and natural philosophy, and became Director of the Observatory from 1857 to 1858. Vail then went on to serve on the Haverford College Board of Managers as a member of several important committees. Vail was also instrumental in the construction of Haverford's library, serving on the committee which insured--during the Civil War--that the library was built, as well as serving on the Committee on Library and Apparatus.
After a long and successful career in the Philadelphia area, Vail and his family moved to Santa Barbara in 1882. He developed an extensive cattle ranch, and was involved in various public works projects in the area to help improve the community. Vail was also able to maintain his personal interests, pursuing research and publishing articles related to meteorology, nature, and astronomy.
Vail died on June 28, 1900, in Santa Barbara.