There were Allens in Franklin and Walker Co.,AL starting in 1815/16 from the David Allen Jr b. in NJ 1761 family. Lots of Johns in that line - many moved west by 1890, but I am sure some stayed in AL from that line. Have you done any DNA testing? There are many who have tested from that line and many other Allen lines listed on the family tree dna site.
Since there are somany Allens in this world one must almost do a yDNA test to narrow down one's line. It is one of the most common surnames. It is very hard to just "trace" Allens by paper trail.