Posted By:
Jason LThe Wisconsin Historical Society has quite a number of vintage baseball photos that you can view online, and even order copies of!
Check them out...dates start at 1886 and go towards 1960...
subjects include Indian teams, school teams, House of David, Babe Ruth, Eddie Mathews, plenty of neat Hammerin Hank, & lots of stuff that they have marked as unknown...perhaps you could help contribute to their knowledge base if you recognize something!
http://www.wisconsinhistory.org/whi/results.asp?pageno=1&keyword1=baseball&search_type=basic&sort_by=date