Bain was born in 1830 at Graaff Reinet, at that stage a frontier town in the Cape Colony in Southern Africa.

Thomas served as a volunteer in the war and helped to guard women and children who sheltered in the church of the frontier town of Fort Beaufort.

Their goal was achieved by the father-and-son combination of Andrew and Thomas Bain, whose civil engineering prowess effected a quantum leap in the quality and range of the road network of the 19th-century Cape Colony.

One of Bain's major achievements was the construction of the road on the coastal plain between George and the forestry town of Knysna.

This road linked Knysna to the more developed areas towards Cape Town and replaced the dreaded river crossing at Kaaimansgat which early travelers described with trepidation.

Then followed the 185 km Tsitsikama road, linking the western and eastern portions of the Cape Colony through the indigenous forests of the coastal plain.

In 1888 Bain resigned from the Road Department and accepted the position of Irrigation and Geological Surveyor of the (Cape) Colony.

His prolific career with the Road Department resulted in a remarkable heritage of some of the most scenic and impressive mountain passes in South Africa.