Late People May Not Be Dead

A reference to an ancestor as being "late of Harford County, Maryland," does not necessarily mean he was dead at the time of the reference. What it usually means is that the person was formerly of that area being mentioned--so this reference means the person used to live in Harford County.

You don't have evidence someone was dead on 1 January 1823 if the only reference to them being dead on that date is the fact that they were "late" on that date.