Final answer:
The Pacific Railway Act was signed in 1862, providing federal government assistance for the railroad, which was completed on May 10, 1869.
Step-by-step explanation:
The timeline of the events related to the creation of the Transcontinental Railroad begins with legislation and ends with the completion of the railroad itself. The Pacific Railway Act, signed by President Abraham Lincoln, occurred in 1862, which essentially provided federal support for the construction of the railroad. Asa Whitney, who was one of the early visionaries and promoters of a transcontinental railroad, made his proposal to Congress in the 1840s, well before any action was taken. Finally, the First Transcontinental Railroad was officially completed on May 10, 1869, when the Union Pacific and Central Pacific rail lines were joined at Promontory Point, Utah.