No. 42 jersey tribute began in 2007 with Griffey

Cincinnati Reds - Today in Reds history 2007: Reds right fielder Ken Griffey Jr. sought permission from then-Commissioner Bud Selig and Robinson's widow, Rachel, to wear No. 42 on April 15. From

Jackie Robinson Day Started with Ken Griffey Jr - Last Word On Baseball

Ken Griffey Jr. Seattle Mariners Authentic Jersey Jackie Robinson Tribute

Ken Griffey Jr.: Road to Cooperstown by The News Tribune - Issuu

Uniform number (Major League Baseball) - Wikiwand

A Measure of Respect for Jackie Robinson Turns Into a Movement - The New York Times

Charlie Blackmon, Rockies appreciate 75th anniversary of Jackie Robinson's debut

In Robinson's shadow – The Denver Post

Ken Griffey Jr. had Jackie Robinson Day idea

Cardboard appreciation: 1977 Topps Carlton Fisk

MLB Honors Jackie Robinson: No. 42 Still Has Impact Throughout Baseball - SB Nation Detroit

Mitchell & Ness on X: 25 years ago today, Ken Griffey Jr. helped honor the iconic No. 42 as players suited up for the field on Jackie Robinson Day. The New Authentic

Ken Griffey Jr. Started Wearing 42 on Jackie Robinson Day! #shorts

Seventy-Five Years Ago, Jackie Robinson Changed History When He Took the Field in a Brooklyn Dodgers Uniform - Jugs Sports