Adam O'Bryan (O Brien), Jr. - Researching marriage, death, birth all records for John Adam O'Bryan, Adam O'Bryan Jr.

Actually I'm searching for all the Cornelius O'Bryan history records.
I'm a descendant.
My father, Patrick Henry O'Brien wife; Hilda Augusta Nelson
grandfather Andrew Jackson Benjamin Harrison O'Brien, wife; Sarah Frances Georgia Jane Webb O'Brien
great grandfather John Mace O'Brien, wife; Malinda Cottrell O'Brien
great great grandfather John O'Brien, wife; Mary Mace O'Brien
great great great grandfather John Adam Jr. or John Adam O'Brien Sr. wife; Elisabeth Bush O'Brien

I've researched since 2001 and no marriage records for John Adam Sr. and Catherine (Katy) Westbrook
Nor Elizabeth and lastly Margaret.

Now Adam O'Brien Jr.? This is the latest I've heard of some family claiming he is my ggg grandfather. :-(

If you have good record for these ancestors could you share........Thank you.....Pam O'Brien Doan