Why did the Union blockade go as far north?

The Union blockade extended as far north as it did to disrupt Confederate trade routes and prevent supplies from reaching the South. By blockading key ports and coastal areas, the Union aimed to weaken the Confederate economy and military capabilities. Additionally, controlling northern ports allowed the Union to maintain a strategic advantage and ensure the flow of resources to its own forces. This comprehensive approach was crucial for the overall success of the Union's war strategy.