Have you checked census records?I find it interesting that William is younger then Mary on 1910 and 1920 census.And, the only Dorris in Ouchita Parish in 1900 is:
Dorris, Burrell, hd, b Jun 1878, 21, M 1 yr, b AL, GA, AL " Mary, w, b oct 1874, 25, m 1 yr, 1 ch, 0 lvg, b LA, LA, GA
Month and year of birth matches Mary's headstone data, and month matches William's.
He consistently shows birth location for himself as AL on 1910 and 1920 censuses.
Now, if he was indeed born 1874 and used "L" for middle initial on a record, what do you think of this Lownde?Birth location for father and mother matches Burrell on 1900 census.
1880 Linwood, Pike Co, AL:
Category: Name;Relationship to head of household; Marital Status; Gender; Race; Age; Birthplace; Occupation; Father's Birthplace; Mother's Birthplace.
Jackson J. DORRISSelfMMaleW44GAFarmerSCSC Luvice DORRISWifeMFemaleW44ALKeeping HouseGAGA Jackson DORRISSonSMaleW15ALLaborer On FarmGAAL Joseph B. DORRISSonSMaleW14ALLaborer On FarmGAAL Anguish DORRISSonSMaleW12ALLaborer On FarmGAAL Asbury DORRISSonSMaleW11ALLaborer On FarmGAAL Lowndes DORRISSonSMaleW6ALGAAL Lizzie DORRISDauSFemaleW2ALGAAL
I don't think members of this family cared for their names.I don't find Anguish or Asbury Dorris on 1900, 1910 or 1920 censuses. (^_^)
You might check land and probate records for Jackson (Sr.) see who shows up as heirs.Allheirs would have to sign off when final sale of land is made.If heirs live out of the area, they often record a power-of-attorney record for someone local to collect their share of an estate, it would be interesting to see if anyone lived in LA.