Due to construction of the transcontinental railroad, immigration to the western united states during the 19th century primarily involved workers from

The Transcontinental Railroad construction attracted many immigrants to the United States. There was a great many Chinese immigrants that came to the western United States and around 14, 000 of them were hired to work under tireless and sometimes brutal working conditions.

B: China

Explanation:

Immigration to the United States during the 19th Century due to construction of a transcontinental railroad PRIMARILY involved workers from China. Due to increased conflict, the Chinese Exclusion Act of 1882 prohibited immigration from China for ten years, and was extended by the Geary Act in 1892. National origin quotas for immigrants were lifted in 1965.

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.