He had 5 sons.

John Butler Williams was born in Landore, Glamorgan, Wales near Swansea. Jack was the eldest of eight boys.

Jack came with his mother and brother Thomas to join their father in Pennsylvania. After a short time in Pittsburgh the family made their home in Fullerton Pennslyvania where his father worked in the Catasaugua Manufacturing Plant.

As a young man Jack came to San Francisco where his widowed grandmother, Charlotte Prosser Williams, was living. There he became a Civil Engineer and met and married his wife, Mary Brown Young. Jack & Mary lived in San Francisco for a time and then made their home in Oakland. In his later years, Jack Williams was a Real Estate Broker.