There is a book called "History of the Town of West Turin" and on page 555 it states that Alphonson was son of Willard Allen.
In 1830 he shows on the Census in Amite MS as head and no one else living with him. Then in 1831 he married Harriett M. Everett. In 1840 they are in Census in Attala MS 1850 in DeSoto Parish LA, but he appears to be a widower 1860 DeSoto Parish shows a Mary age 35 ??, 1870 still DeSoto married to Laura E. 1880 Desoto Parish 1900 Laura E is widow living in Vernon Parish with their youngest son Horace. You'll find all his children listed in Censuss Records.
Louisiana Land Records about Alphonson Allen Name: Alphonson Allen Land Office: NATCHITOCHES Sequence #: 1 Document Number: 11463 Total Acres: 80.58 Signature: Yes Canceled Document: No Issue Date: 1 Apr 1859 Mineral Rights Reserved: No Metes and Bounds: No Statutory Reference: 3 Stat. 566 Multiple Warantee Names: No Act or Treaty: April 24, 1820 Multiple Patentee Names: No Entry Classification: Sale-Cash Entries Land Description: 1 W½SELOUISIANA No 12 N 12 W 3
Mississippi Marriages, 1776-1935 about Alphronson Allen Name: Alphronson Allen Spouse: Harriet M. Everett Marriage Date: 1 Feb 1831 County: Amite