Not the first time the usa army was sent to fuck over usa citizens. Two notable ones from that list:

In 1877, workers on the Baltimore & Ohio Railroad staged a walkout over scheduled wage cuts, provoking a nationwide general strike that paralyzed commerce across the emerging industrial belt of the Midwest and mid-Atlantic states. (…) From Washington, Hayes ordered the Army to break the strike, which it did with overwhelming force

During the early days of the Great Depression, thousands of World War I veterans camped in Washington, D.C., demanding early payment of bonuses owed to them in later years. Hoover, fearing radicalism and facing pressure from the business community, ordered the veterans forcibly removed from several federal buildings they were occupying. Active-duty troops under General Douglas MacArthur exceeded that order, deploying tanks and cavalry, setting the Bonus Army’s camps on fire and routing the protesters.

Not mentioned in that article, but also relevant, Battle of Blair Mountain - usa army sent to stop coal miners’ strike