Thomas was the eleventh and last child of Dr David M. Buchan and Nancy Jane Lancaster of Pulaski County, GA.

His father, David, and grandfather, Dr James Monroe Buchan, were well respected medical doctors in Georgia.

Thomas was married for 43 years to Elise Josephine Wescott Buchan of Orlando FL.

After their marriage, Thomas and his family lived next to one of the first airports in Orlando FL at the corner of what was then called Buchan Street (now John Young Pkwy) and Old Winter Garden Road.

Thomas and Elise had nine children, seven of whom grew into adulthood. His main occupation was as an auto and airplane mechanic, but he was also a skilled carpenter. After retiring, Thomas engineered an innovative rabbit and fishing worm housing complex. He sold rabbits and fishing worms as far away as California.

He loved fishing.

Thomas, his wife and two of his sons were fishing at the east coast of Florida when Thomas died from a massive heart attack. He was brought home to Orlando and buried in the family plot at Greenwood Cemetery.

The children of Thomas and Elise:

Nancy Elise Buchan 1915–1999
Baby Boy Buchan 1916–1916
Walter Monroe Buchan 1917–1978
Thomas Frank Buchan II 1919–2008
Georgia Martha Buchan 1921–1998
David Leoline Buchan 1924–1998
James Hector Buchan 1926–2002
Joseph "Joe" Earl Buchan 1927–1934
John Melvin Buchan 1934–2012