Fidel Velázquez was secretary general of the Confederation of Mexican Workers (CTM) for about five decades. Biografías y Vidas states that he held the post “desde 1941 hasta su muerte” (from 1941 until his death). Encyclopedia.com gives two terms instead, from 1940 to 1946 and again from 1950.
He died in June 1997 at the age of 97. The Deseret News, reporting his death, called him “a kingmaker” in the ruling party.