What did Lincoln believe would happen if he didn't prevent Maryland from seceding?

Washington, D.C. is our nations capital. It
was
created when Maryland and Virginia donated land as part of the compromise to deal with
our
nations debt. Since Maryland and Virginia were considered part of the
South, there could be
issues if the country ever split along regional
lines.

When Virginia decided
to secede from the Union,
President Lincoln knew there could be an issue with our capital. Since

Maryland had slaves, there was a very good possibility that Maryland could secede from
the
Union. If Maryland seceded from the Union, our capital would be cut off
from the Union. It would
have been located in the Confederacy. As a result,
President Lincoln had to be sure Maryland
stayed in the Union.

To prevent the Maryland legislature from voting to
secede, President
Lincoln ordered the arrest of those legislators that supported secession.
This
prevented Maryland from seceding. By keeping Maryland in the Union as a
border state, our
capital wouldnt be cut off from the
Union.