Here's a Business Insider article that goes into a lot more detail about what Russia's Internet Research Agency (IRA) was most interested in to cause maximum discord in the U.S. population, and of course it was race relations.
From the article:
The Internet Research Agency, the notorious Russian troll farm at the center of these efforts, "heavily focused on hotbutton issues with racial undertones, such as the NFL kneeling protests."
If you feel so inclined, the link also includes the entire report.
From the article: