https://www.baseball-almanac.com/recbooks/rb_hr7.shtml https://www.baseball-almanac.com/recbooks/rb_hr7.shtml by seven teams all-time record accomplished the feat "Home Run Records by a Team During a Single Season" Home Run Records by a Team During a Single Season ”Home Run Records by a Team During a Single Season” http://www.baseball-almanac.com/recbooks/rb_hr7.shtml 1997 Seattle, 264 by seven teams MLB RECORD by seven teams