[DiogenesLamp]

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.

This does not speak to what the vote tally would have been prior to the armed conflict beginning. If they were so solidly Union, why were legislators getting arrested?

[BroJoeK]

DiogenesLamp: "This does not speak to what the vote tally would have been prior to the armed conflict beginning.
If they were so solidly Union, why were legislators getting arrested? "

No Maryland legislators were arrested -- none, zero, nada - legislators arrested prior to the first vote on secession, April 29, 1861.
That vote was 53-13 against secession, four to one, a pretty fair indicator of Marylanders' feelings at the time.

After that vote the Confederacy formally declared war, on May 6, 1861, and then and only then did any arrests in Maryland begin.
No legislators were arrested until September, 1861.

So the real issue in states like Maryland, Kentucky and Missouri was whether majority vote would rule against secession, and as it turned out, the majority did rule, despite strong pro-slavery opposition.