The correct answer is letter D
The authorization for the construction of the railway came through the Pacific Railway Act, which took place in 1862 with support from the United States government. However, for many decades, there was a movement that called for the beginning of the development of the railway. The beginning of the works was the outcome of attitudes from the time when Abraham Lincoln presided over the U.S., however, the project was only completed after his death.
With the construction of the First Transcontinental Railway, it was possible to connect the coasts of the Pacific Ocean with the Atlantic Ocean. For the first time in history, a railway network connected two sea coasts and, thus, the project is still a reference in the field of railway construction.
This is due to the fact that the construction of the First Transcontinental Railway was very difficult. For its development, several applications of engineering and work techniques were necessary, as the railway had to pass through high mountains and various types of plains through the Union Pacific Railroad and Central Pacific Railroad, which gave rise to the eastern and western lines.
