what did the immigrants from Denmark between 1820-1850 contribute to America?

Question

How did the effect American society and culture?

Answer 1

http://www.amazon.com/Harvard-Encyclopedia-American-Ethnic-Groups/dp/0674375122

See if your library has this one.

I've read a bit about Danish migration to America, and I suspect the answer to your question is: not a lot. Unlike Swedes and Norwegian who settled in a small number of states and intermarried quite a bit (for a few generations), Danes more or less assimilated immediately, became Americans and were never heard from again :).

Solvang, California, was a bit of an exception to the rule:

http://en.wikipedia.org/wiki/Solvang

Answer 2

Do your own homework.