1900 Census, Aleppo Twp., Greene Co., PA:
Grim, Armstrong, b. May 1858, 42, married 13 years, b. PA, father b. WV, mother b. PA, farmer
Jennie E., wife, b. May 1859, 41, married 13 years, 3 children, 3 survive, b. OH, father b. OH, mother b. MD
Raymond, son, b. April 1888, 12, b. PA
Florence C., daughter, b. April 1890, 10, b. PA
Olive A., daughter, b. June 1898, 1, b. PA
Armstrong was living next to his father, Isaac Grim, at the time of the census.

1910 Census, Aleppo Twp., Greene Co., PA:
Grim, Armstrong, 52, married 23 years, b. PA, parents b. PA
Jennie E., wife, 41, married 23 years, 3 children, 3 survive, b. OH, father b. OH, mother b. MD
Florence E., daughter, 20, b. PA
I.?, daughter, 11, b. PA (must be Olive)

Armstrong lived in Bristoria, Greene Co., PA in 1918 when his father died.1054