Susanna Bishop Marble (1784-1861), the principal author of these letters, married Simeon Marble (1777-1856) in 1797 in New Milford, Conn. They had five children (Adeline, Susan B., Jane Louisa, Edwin, & Mary H.). Jane Louisa Marble Day (1809-1893), to whom the letters are addressed, was married to Henry Noble Day (1808-1890), a minister and professor of theology at Western Reserve College in Hudson, Ohio. The "Henry Mills" and "May Elizabeth" referred to in the letters are Jane Louisa and Henry Day's children. The others co-authoring Susanna B. Marble's letters are her son Edwin Marble (b. 1812), her daughter Mary H. Marble (b. 1816), her husband Simeon Marble, and Edwin's wife Julia.
Simeon and Susanna Marble were living in New Haven, Connecticut, during the decade they wrote these letters. Their daughter Mary H. Marble was living with them, as was their son Edwin, until his marriage in 1846. By 1853, Edwin and his wife Julia were living near his dry goods store on Chapel St. Simeon Marble appears to have been in the building or remodeling business. Susanna was a secretary and treasurer of the Dorcus Society in New Haven from 1840 to 1843.
From the guide to the Marble family papers, Marble family, 1834-1851, 1841-1851, (William L. Clements Library, University of Michigan)