Athletes and social movements have had a long history -- almost as long as pro sports itself. The Undefeated created a list that goes back to 1883.

But in August, all of the major professional sports in North America went dark following the shooting death of Jacob Blake in Kenosha, Wisconsin.

In this episode of This Is Why, we look at why pro sports leagues are finally getting behind their athletes in calling for change.

Contact:

Adam Toy - @Adam_Toy on Twitter

Dave McIvor - @d_mac1519 on Twitter

This is Why - @ThisIsWhy on Twitter

Email us - [email protected]

Guests:

Bruce Arthur, columnist, the Toronto Star