What year did Little Women take place?

Little Women by Louisa May Alcott
takes place during and after the Civil War.  I know this because, in the first chapter,
Mr. March is a chaplain in the army.  Meg, awaiting the letter Mrs. March is about to
read says she is proud of him for going as a chaplain as he was too old to be drafted. 
I know this takes place during the Civil War because Joe states she will try to be a
"little woman" for him after hearing the letter, and then the text says that Jo felt
that would be a lot harder than facing a rebel or two down South.  This also clearly
shows that Mr. March is in the Union army because of Jo's
statement.