The slave states that did not secede and did not join the Confederacy were Delaware, Maryland, Kentucky, and Missouri , usually called the “border states.” These were slaveholding members of the Union that stayed officially loyal to the United States throughout the Civil War.

Core answer

  • The commonly recognized slave states that stayed in the Union and did not secede are:
    • Delaware
* Maryland

* Kentucky

* Missouri

These four are often grouped together under the label border states because they bordered the seceded Confederacy and were strategically crucial to the Union war effort.

Quick extra context

  • All four legally permitted slavery at the start of the Civil War but kept their representation in the U.S. Congress and never achieved official, recognized secession.
  • West Virginia, which split off from Confederate Virginia in 1863, entered the Union as a separate state and also still had slavery for a time, but it is usually treated separately because it was created during the war rather than being an existing prewar state that chose not to secede.

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