Question: Who wrote a letter to Orville Browning where he recognized the importance of one of the four slave states that never declared a secession in the Civil War?

Related documents: [0]  [DOC] In the context of the American Civil War (1861–1865), the border states were slave states that did not declare a secession from the Union and did not join the Confederacy. To their north they bordered free states of the Union and to their south they bordered Confederate slave states. Of the 34 U.S. states in 1861, nineteen were free states and fifteen were slave states. Four slave states never declared a secession: Delaware, Kentucky, Maryland, and Missouri. Four others did not declare secession until after the Battle of Fort Sumter and were briefly considered to be border states: Arkansas, North Carolina, Tennessee, and Virginia—after this, they were less frequently called “border states”. Also included as a border state during the war is West Virginia, which was formed from 50 counties of Virginia and became a new state in the Union in 1863. [END] 
[1]  [DOC] Kentucky was a border state of key importance in the American Civil War. President Abraham Lincoln recognized the importance of the Commonwealth when, in a September 1861 letter to Orville Browning, he wrote: [END]  
Answer: Abraham Lincoln
Abraham Lincoln