What is the most northern middle Atlantic colony

They could be:

Pennsylvania, New Jersey, New York, and Delaware.

Hope this helps :)

The Union blockade in the American Civil War was a naval strategy by the United States to prevent the Confederacy from trading. The Union commissioned around 500 ships, which destroyed or captured about 1,500 blockade runners over the course of the war

Explanation:The fall of Mobile Bay was a major blow to the Confederacy, and the victory was the first in a series of Yankee successes that helped secure the re-election of President Abraham Lincoln (1809-65) later that year.