Mary E. Smith was born around 1843 in Louisiana. She corresponded with John I. Irwin throughout the Civil War. In May 1864, he wrote that “I sometimes think if by some magic power, I could be transported over to your part of the country [Mobile, Alabama], I would be the happiest creature on earth…patience and we shall see.” She encouraged him to “write oftener,” noting that his “letters always affords me the greatest pleasure.”
The couple got married in the Third Presbyterian Church in New Orleans, Louisiana, on April 30, 1872. They had at least four children: John, born around 1874; Josephine, born around 1876; Marian, born around 1878; and Harriet, born around 1879. They lived in New Orleans, and her husband worked as a clerk. Mary died around 1880.