I have updated information regarding the Richard Jacob Allen I am researching.
Richard Allen did not die in Missouri, as I previously thought. He along with his wife, Narcissa Mathilda Merrill Allen, died in Texas in or around the Dallas Co., or Cedar Hill area in 1869. The death date is the same for the pair.
I do know that Narcissa Mathilda Merrill was the daughter of David Alexander Young Merrill. I do know that Narcissa and Richard Jacob Allen had one child named Melvina McCullah Allen. After the demise of her parents in 1869, she went to live with the brother of Narcissa, David Alexander Merrill, know as Alex. Alex was 27 or 28 at the time.
If anyone has knowledge of Richards line , I would be pleased to know it!