What was a difference between immigrants who arrived in the united states during the 1840's and the 1850's and the 'new' immigrants who began arriving in the 1870s?

There were a lot of differences between old and new immigrants like origin, number, religion, profession, language.

Explanation:

Old immigrants principally came from Northern and Western Europe in smaller groups, most of them were protestant farmers, who spoke English and easily assimilated the change.

New immigrants principally came from Northern, Western, Southern and Eastern Europe and Asia in larger numbers, They were from different religions like Jews, Catholics, and Eastern Orthodox, they principally worked in construction and factories. Few spoke English and many spoke Greek, Italian, Russian, polish. etc... because of so many differences, they found it more difficult to assimilate the change.

adopted the practice of proskynesis, a persian court custom that involved bowing down and kissing the hand of others, depending on their rank.

the main concern with the first draft of the articles of confederation was too much power in the state governments.