August 10th marks the 45th Anniversary of Harmon Killebrew's 500th Homer. The milestone occurred in the first inning of a Twins 4-3 victory over the Baltimore Orioles
2015 Topps #H-74 Harmon Killebrew 500 Home Runs.
The event was honored in Topps 2015 Highlight of the Year insert.
A brief synopsis on the back of the card also notes that the hit was part of a pretty big day for Killebrew in which he had a pair of Home Runs, both lead changers, and 3 RBIs.
Sources and Links
Phungo Harmon Killebrew HoF Page