Answer:
The population of United states will be low.
Step-by-step explanation:
The railroads sought immigrants for its labor because labors are needed for the building of railroads. The immigrants labor were good for this work due to taking low wage for the work as compared to local workers who demanded more money for the work because the work is very hard. If these immigrants did not come for the work of railroads so the population of United States of America is lower than the present population of United States.