Los Angeles Herald, 10 May 1900 GRIFFIN THE VICTOR—AI Griffin, the heavyweight local champion, defeated Jack Munroe at Watsonville last Saturday, news of which reached the city only yesterday. Munroe won the heavyweight championship at the Olympic club tournament for amateurs, and was considered a coming man in his class. Griffin will now be matched to fight the winner of the Russell-Kennedy fight, which will take place before the Columbia club at San Francisco the latter part of this month. https://cdnc.ucr.edu/cgi-bin/cdnc?a...20--1--txt-txIN-%2522jack+munroe%2522-------1
https://chroniclingamerica.loc.gov/lccn/sn84028140/1902-12-23/ed-1/seq-3/#words="jack+munroe" This also mentions him being the Olympic Club amateur champion of the pacific coast. https://www.amazon.ca/Legend-Jack-Munroe-Portrait-Canadian/dp/0887532551 It's also mentioned here
