My daughter is member of DAR. There are oral traditions that still survive. Not as much for the American Revolution as the later Texas Revolution. But there were some overlaps between the two.
My ancestors were here during the Republic of Texas, my father’s grandfather was born in TX during the Republic. Those oral history events still survive, not hear say.
You don't get any more "hearsay" than oral histories passed down through multiple generations. That's about as unreliable as it gets.
If you want reliable, read things that were written by the very people who lived through those events. That way, you are getting it in the words chosen by the people who actually were there, written in their own hand so you know it hasn't been changed or distorted by subsequent listeners.
That still isn't perfect, because individuals have their own perspective and viewpoints that may not reflect fairly what actually happened. It's like pulling a random 70 year old off the street 40 years from now and asking them about Trump. Exactly who that person is would make a huge difference in terms of what you are likely to hear.