Which of the following groups of peoples made up most of the workers on the railroad? a. native americans, mexican americans, and south americans b. factory workers, cattle ranchers, and sailors c. confederates, abolitionists, and free masons d. chinese and irish immigrants, and african americans

D. Chinese and Irish immigrants, and African Americans

Explanation:

Between 1800 and 1950, more than 40 million immigrants entered the United States, this proved that there was a great variety of labor. Most of the first railroads that were built in the US, were built by Irish, Chinese immigrants and some veterans of the Union and Confederate armies. For these great works, blacksmiths, carpenters, engineers, masons, surveyors, truck drivers, telegraphists and even cooks were needed, to mention just some of the work involved in the construction of the railway.