What was the purpose of bradford’s of plymouth plantation?

I haven't read Smith's writing but I have Bradford's "Of Plymouth Plantation". It's a handwritten journal documenting the events of the first 30 years of the Pilgrims and Plymouth Colony. The writing is a blend of facts and interpretations which gives the reader the true picture of how life was at that time. It is said that Bradford wrote the journal because he wanted to make sure that future generations could gain insight and wisdom from the successes and failures of the Pilgrims' first years.