Mordecai M. Kaplan began his life's journey with the confines of a small Lithuanian town on the outskirts of Vilna. He was born on a Friday evening in June of 1881. Kaplan's submergence in a total Jewish atmosphere is illustrated by the fact that he knew his day of birth only by the Jewish calendar until he went to the New York Public Library as a young man to look up the corresponding date. Kaplan's family was a traditional one in every aspect, and his father, Israel Kaplan, was a learned man.
Mordecai Kaplan wrote a lot of books. It's hard to decide which ones to read. But this compilation of short excerpts from several of his books is a good introduction to his thinking.