Question

Which event happened prior to President Lincoln signing the Pacific Railroad Act in 1862?

Answer 1

I believe that Asa Whitney requested the right to build a transcontinental railroad.
 

Answer 2

We can point out some significant events that happened prior to President Lincoln, who was elected in 1860, signed the Pacific Railroad Act, such as:

The Southern secession - Separation within the Democrat party into northern and southern sectors. This event contributed to the success of the republican party of Lincoln and was the direct cause of the secession;

Civil war begins - Lincoln made it clear that secession was unconstitutional and the war came when the federal government tried to resupply forts in the South.

July 1861  - First Battle of Bull Run (Manassas)

July 1862 - Peninsular campaign

April, August, September 1862 -  Battles of Shiloh, Second Bull Run, and Antietam