Frontiers of '49 (1939)

In California in 1848, Brunton through his stooge Sheriff is evicting the Mexicans from their ranches. Major John Freeman and his troops arrive to investigate. Keeping his troops hidden and appearing out of uniform, he takes up the fight against Brunton. He helps a rancher who has been evicted before his taxes were due only to find him murdered and this leads to the showdown between Brunton's men and the soldiers.

Unfortunately the movie Frontiers of '49 is not yet available on HBO Max.