Boston Celtics replicate 1960's unity demonstration during national anthem

Before Tuesday night's game vs. the Philadelphia 76ers, the Boston Celtics demonstrated unity during the national anthem by locking arms:

This was a planned action by the team, as told by Celtics coach Brad Stevens:

"We've had a lot of sit-down discussions about it ... We've had a lot of individual discussions. We've had three or four meetings with the team after practices; sometimes just the players, sometimes just us, sometimes people that we've invited in from the outside to spend time with our guys. Our guys have been incredibly thoughtful."

The demonstration may look familiar to some of the older audience members and/or TV viewers, as this same expression was done by the Celtics during the 1960-61 season to raise awareness amid rising racial tensions in the country:

As "The Star Spangled Banner" was performed, the Celtics' Twitter account published a video from the team's players:

A subtle, yet powerful message.