Notes:
Data source is John Hess Calaman. email john.calaman@gmail.com
Is living with his wife in the house of his father in the 1900 census
In 1910 his father-in-law is listed as living with them. May is shown as having given birth to 2 children with 2 living, but they are not shown in the household. Edgar and May are listed in the 1920 & 1930 census with their 2 sons. I expect that their 2 sons were simply left off the 1910 census by accident when the data was transcribed.
1900 Census, PA, Dauphin Co., Lower Paxton Twp, 6 June 1900, ED 85, Sheet 4, page 119B
Mumma, Edgar, head, Apr 1859, 41, married 24 years, b. PA, Fa: PA, Mo: PA, occ: farmer
" Ellenor, wife, Jan 1858, 42, married 24 years, 3 children & 3 living, b. PA, Fa: PA, Mo: PA
" Edgar, son, Nov 1878, 22, married, b. PA, occ: farmer
" May, daughter in law, Mar 1879, 21, married, b. PA
" John, son, Mar 1890, May, 1890, 10, single, b. PA
" Ella, daughter, May 1892, 8, single, b. PA
1910 Census, PA, Dauphin Co., Susquesana Twp., p. 247
Mumma, Edgar C., head, 32, M1 23 yrs, b PA/PA/PA, salesman, piano
" , May M., wife, 31, m1 31 yrs, 2 children, 2 living, b. PA/PA/PA
Brightbill, David W., father-in-law, 71, B. PA/PA/PA, own income
1920 Census, PA, Dauphin Co., Lower Paxton, Twp., p. 217
Mumma, Edward, head, 43, b. PA/PA/PA, salesman, piano
" , Mary M., wife, 40, b. PA/PA/PA
" , Ellis B., son, 16, b. PA/PA/PA
" , Russel J., son, 14, b. PA/PA/PA
1930 Census, PA, Dauphin Co., Lower paxton, Twp. p. 149 Indexed as "Mulvenna"
Mumma, Edward C., head, owns $9000, 52, 1st married @ age 21, b. PA/PA/PA merchant in ? shop
" , May M., wife, 51, 1st m. @ age 20, b: PA/PA/PA
" , Ellis B, son, 27, single, b: PA/PA/PA clerk stock provision co
" , Russel J., son, 24, single, b: PA/PA/PA, salesman, music