Background
He was born on August 19, 1884, on Martha's Vineyard, Massachussets, the eldest of the four sons of William and Julia Adelaide (Sprague) Barbour. His father was president of Barbour Brothers, a flax-spinning company, a director of the linen mills of William Barbour and Sons in northern Ireland, and head of many other firms in many fields of business. Barbour's mother came from a prominent New York family; his brother, William Warren Barbour, became a United States senator from New Jersey.
Barbour's interest in natural history developed at an early age. It was nurtured by his father, a lover of the out-of-doors, who, taking the family with him on many of his business trips abroad, exposed the children to nearly all the major natural history museums in Europe. Observation of creatures in the wild was also encouraged by his father, who had a large estate on Tupper Lake in the Adirondacks, where Thomas spent many vacations in his youth, and by his paternal grandmother, whom he visited a number of times at her home, Walden Cottage, at Eau Gallie, on the then almost unsettled east coast of Florida. He was an enthusiastic fisherman and hunter all his life, but he tended even as a boy toward the scientific study of animals, particularly reptiles and amphibians, the field of herpetology.