I have never been able to definitely determine where Hiram Day was born because of the discrepancies in the census. The 1850 census has Ohio, 1860 has D.C., 1870 has Pennsylvania, and 1880 has Washington City. The information on the death certificate would have been provided by John Morgan Day, my husband's gr-grandfather. I do not have any information on Margaret Davis Day's family.
I have the following children for Hiram and Margaret:
i. Malinda, b. 1842, married Benjamin Wiemer
ii. Theadore, b. 1845, m. Charlotta ?
iii. William Day, b. 1848, d. before 1860
iv. Martha, b. 1852
v. Mary E., b. 1852
vi. John Morgan Day, b. May 22, 1856, m. Barbara Baker, May 19, 1887, d. December 2, 1943
vii. Ann E., b. 1859
I would welcome any additional information on Malinda's family as I have only found her in the 1870 census with children Estelle, William and Hiram. The surname was spelled Wimer on that census.
I also would gladly share what I do have.