He is living in Alton, MO in 1920, working as a laborer (23, MO) for the city, with his wife Leila (24, IL) and daughters Esther and Opal, both born in Kansas.
He is listed as a farmer (34, MO) in the 1930 census for Jasper Twp, Ralls Co, MO with his wife Lila and 4 children as well as his “widowed”? mother.
In the 1940 census, Ernest is listed with his wife and 2 sons in East St Louis.
He was living in Mountain Grove MO in 1931-32, then in East St Louis IL in 1942 when he registered for the WWII Draft. He was living in Glenellen, MO in 1950 when his father lived with him due to illness and died at his home.
[Obituary] The Belleville News-Democrat, Belleville IL - Tuesday, 28 March 1967, pg 2
Ernest Armstrong of Tilden dies at Home Monday
Ernest E. Armstrong 71, died unexpectedly at his home in Tilden Monday morning. He had been in failing health for several years. Before his retirement he was employed by the Hunter Packing Co, in East St. Louis for 27 years.
Funeral services were held Wednesday afternoon at the Finger Funeral Home in Marissa followed by burial in the Marissa Cemetery, Rev. Wesley P. Walters, pastor of the United Presbyterian Church of Marissa, officiated.
Mr. Armstrong was born January 19, 1896 in St. Louis, a son of the late Wyman 0. and Susan Jane Armstrong nee Box. On September 15, 1960, he was married at Sparta to Mrs. Amy Cooper, who survives.
Other survivors are two sons, Harley Armstrong of Cahokia, and Francis Armstrong of Caseyville; two daughters, Mrs. Esther Janco of Granite City and Mrs. Opal Swindell of Clay City: a step-son, Raymond Cooper of Tilden; two step-daughters, Mrs. Lorene Casperson of Arthur and Mrs. Pauline Schmidi of East St. Louis; two sisters, Mrs. Mabel Tucker of Waieiloo, Iowa and Mrs. Jennie Atchison of Marshalltown, Iowa; a half-brother, Sid Adkins of Hot Springs, Ark.; 14 grandchildren; four step-grandchildren, and 15 great-grandchildren.