Georges Carpentier fought from 1908 - 1926 started at 105 pound straw weight finished at 175+ pound "Heavyweight" by todays standards of multiple belts he may have collected a paper World heavyweight title in an equivalent era eg 1978-2002 or some S**t Guillermo Jones has gotten close so far 147 - 200 pound current Cruiser World champ he still has time to make noise at Heavy since they fight Old 40+ these days quite well
Professionally Floyd 130 to 154, Manny 106 to 150 But yeah I think it's alot easier to go from low weights to welter and most fighters who do tend to be too tall for the lower weights,
Won the WBA strap at 154 lost it in a rematch, weirdly went up to 200lbs like 10 fights later and won the WBO title
Langford beat the lightweight champion in a non title fight and years later won the coloured championship. Fitzsimmons, when he beat nonpareil, the limit then wasn't far above 154. Mickey Walker was the WW champ and fought for the HW title.
Young Stribling won a state featherweight title, and later went onto challenge Schmeling for the heavyweight title. Kid Lewis won the welterweight title, and later challenged for the European heavyweight crown (although it was against the aforementioned Carpentier) Langford and Carpentier are the best shouts for fighters who could have collected titles from 154 to heavyweight in an alphabetised era. Both held versions of the heavyweight title, and were world class at lower weights. Langford obviously is in a different class, and he is the only fighter I can think of with a legitimate claim to being an ATG at every traditional weight class from 147 upwards.