A Brief History of the Single Season Homerun Record

 

 Source:  http://exhibits.baseballhalloffame.org/ss_home_run/ruth_60th_photo.htm

The National Baseball Hall of Fame website has a great timeline of the single season homerun record.  Starting with just 5 HRs by George Hall in 1876 to the current (and disputed) 73 by B.B. whom I refuse to name or give credit.  It's a great story that you can read in 5 minutes.  It's worth the read.
http://exhibits.baseballhalloffame.org/ss_home_run/index.htm