banks first commanded a military district in eastern maryland, which notably included baltimore, a hotbed of secessionist sentiment and a vital rail link. banks for the most part stayed out of civil affairs, allowing political expression of secessionism to continue, while maintaining important rail connections between the north and washington, dc. he did, however arrest the police chief and commissioners of the city of baltimore, and replaced the police force with one that had more carefully vetted pro-union sympathies. in august 1861, banks was assigned to the western district of maryland. there he was responsible for the arrest of legislators sympathetic to the confederate cause (as was john adams dix, who succeeded banks in the eastern district) in advance of legislative elections. this, combined with the release of local soldiers in his army to vote, ensured that the maryland legislature remained pro-union. banks's actions had a chilling effect on confederate sentiment in maryland. although it was a slave state, it remained loyal through the war.