Why did Abraham Lincoln order a blockade of Confederate ports in 1861?

In April 1861, President Abraham Lincoln proclaimed a naval blockade of Confederate ports as a key component of the Anaconda plan, a military strategy proposed by General Winfield Scott to suppress the Southern insurrection.123

The primary objective of the blockade was to "strangle" the Confederate economy by restricting its ability to conduct commerce with other nations, thereby depriving the South of essential resources and revenue. By cutting off Southern ports, the Union aimed to prevent the Confederacy from exporting goods like cotton and importing necessary military supplies, manufactured articles, and medicines.23

Although the blockade was initially challenged in court—leading to the Prize Cases—the Supreme Court ultimately upheld Lincoln's actions, ruling that the president possessed the emergency authority to resist insurrection even before a formal congressional declaration of war. While the blockade did not become fully effective until late 1863, it eventually played a decisive role in the Union's victory by systematically weakening the Confederacy's capacity to sustain its war effort.45