All three March sisters who survive the book get married. Amy marries the wealthy Laurie. Meg marries the impecunious John Brooke, and Jo eventually marries the equally poor Professor Bhaer. While there are differences in fortune, none of the girls marries outside their social class. The Laurences are much richer than the March family, but they are next-door neighbors and move in the same social circles in Concord. Mr. Brooke is poorer, but he is a gentleman: well-educated and well-mannered. The same is clearly true of Professor Bhaer. Jo's first impression of Bhaer is that he is not at all handsome, but "his linen was very nice, and he looked like a gentleman."

When discussing the marriage of Meg and John Brooke, Mrs. March refers to Brooke's lack of wealth as a circumstance which, like Meg's youth, will be remedied by time. Jo thinks the same. There is no great difficulty in marrying a poor man. He will be able to "make good" somehow. To marry a man who was not a gentleman, however, would be unthinkable.

All this makes nineteenth-century America sound very much like nineteenth-century Europe, but there is one crucial difference. Being a gentleman is seen very much as a personal quality. It means knowing how to behave and to dress, and it means being well-educated and ethical. It is not a matter of one's ancestors, who are never mentioned in any case. Marrying within one's social class is viewed within the book as primarily a practical matter, ensuring that husband and wife have similar values and aspirations.