Any division with Robinson and KG is going to be right up there but to be absolutely honest, although there were a lot of good fighters at the time, it wasn't deep type deep. Early 1900s: Joe Walcott, Rube Ferns, Matty Matthews, Billy Smith, Frank Erne, Peter Jackson, Early Sixties: Griffith, Rodriguez, Loi, Fernandez, Ortega, Stable, Cokes. Late seventies: Leonard, Benitez, Palomino, Shields, Duran, Hearns, Cuevas Mid nineties: Whitaker, Trinidad, Quartey, McGirt, Espana, Oscar, Forrest I'd go for the 1900s maybe.
I don't think there has been a weak decade,eg , the 1930's gave us: Armstrong Burley Petrolle McLarnin Garcia Ross Corbett111 Cocoa Kid Williams Zivic
At first glance, i thought that the thread title was "which welterweight was the strongest", lol,....but hey, that would be an interesting thread because rarely is a fighter in the divisions below middleweight assessed in terms of physical strength. Strength of the division historically, I'd go with the SRL, Benitez, Hearns & Duran conglomerate....and for strongest individual welter, I'd say Griffith.:smoke