[DiogenesLamp]

Maryland pro-Confederates were strong in their support of secession and war against the United States, but they were a distinct minority, outnumbered about three-to-one by Unionists.

After Lincoln started arresting them, i'm sure many declared themselves to be against secession. Who can say what it would have been had Lincoln not arrested people?

[BroJoeK]

DiogenesLamp: "After Lincoln started arresting them, i'm sure many declared themselves to be against secession.
Who can say what it would have been had Lincoln not arrested people?"

But of course we already know that answer, since the Legislature voted on April 29 -- before anybody was arrested and before the Confederacy formally declared war (May 6, 1861) -- Maryland's legislature voted four to one (53-13) against secession.

Remember, in every Southern state the vote for or against secession depended on how many slave-holders there were.
In states like Maryland slave-holders were a distinct minority and so no majority for secession was ever seen.
In Upper South states like Virginia & Tennessee slave-holder interests were the majority overall, but large regions opposed slavery and secession.
Hence, for examples, the state of West Virginia and Unionist East Tennessee.