Historical book about friends with "Tree" in title

[Chantal]

I'm looking for a book that was possibly published between 1997 and 2005. It has "tree" in the title and covers a lot of US history. At the beginning of the book women are not able to vote. The book is centered around two friends who don't want to marry. They start a book club instead. Each chapter has the names of the book club members--who joined and who left. Eventually, the founding members of the book club do marry. One of them marries someone of German descent. Its a long book about 800 pages.

[Juels]

...And Ladies of the Club by Helen Hooven Santmyer?

Under the Almond Trees by Linda Ulleseit?

[Chantal]

Thank you Juels.

[Rainbowheart]

Was it either of Juels' suggestions?

If not, you might want to check the Book Clubs in Fiction list.