So why did Lincoln imprison the Maryland legislators without trial? A great puzzle the hindsight probably can’t solve.
A mob had gathered outside the state house in Baltimore demanding secession.
When Lincoln was appraised of the situation he sent troops to guard the statehouse.
The elected members of the Maryland legislature supported the Confederacy. On the other hand, the people did not want to break the Union. In the election of 1860, the Democratic Party split three ways on the Presidency (Bell, Breckenridge, and Douglas). If they had not, Lincoln might not have won and the Southern states would not have seceded.
Besides to offer support for the insurrection 160 years later, how is this relevant? Only 30 legislators were imprisoned, so they hardly represented the majority. However, while its unclear whether Lincoln’s actions were legitimate use of war powers, it’s plain that Maryland was in a state of war. Its own Governor destroyed the bridges and railways around Baltimore to prevent their use by union troops heading South.
It was September 1861. The Maryland Legislature had already voted against secession the previous April and now a minority of members want to take the state to join the armed rebellion currently being waged against the government. What the heck did you expect to happen?
If they voted to secede the government would have had to abandon on DC.
“So why did Lincoln imprison the Maryland legislators without trial? “
I think that explains the resulting “pro-Union” sentiment more than any change of heart.
Another imprisoned civil war Marylander was Francis Key Howard, grandson of Francis Scott Key:
“imprisoned for treason for fourteen months at Fort McHenry in September 1861”
“Howard was the editor of the Daily Exchange, a Baltimore newspaper sympathetic to the Confederacy. He was arrested without a warrant just after midnight on September 13, 1861 at his home by U.S. Major General Nathaniel Prentice Banks on the direct orders of General George B. McClellan enforcing the policy of President Abraham Lincoln.”