Jakab was born in 1905 in Középlak. He immigrated with his brother Adolf in 1920. He settled in Cleveland and changed his name to Jack. He married Sadie Fineman (1907-1995) in 1930. They had three children, Judy (1931-1995), Sally (1937-1939), and Andy (1941-2019). Jack was a carpenter, contractor, and house painter. He started a house painting business with his brother Sandor (Alex), where many family members worked. Jack died of a heart attack in 1952.