08 October 2013
Lucinda and Lucy Ann In One Document
The reason in this case is fairly simply--or at least that's how it appears. The bride signed the letter, but someone else wrote it based upon the handwriting of Lucy Ann's signature and the rest of the document. John L. James (the witness) may have written it as his "L"s are similar to the ones in the document. They are not exactly the same, but the "J" in "John" and "James" aren't really the same either.
At any rate, who wrote the letter may have known Lucy Ann by Lucinda and so that's how the letter was written. Lucy may not even have been able to read, or if she was literate she might not have been concerned that she was referenced as Lucinda in the text of the letter.
Names that are reasonably consistent are not problems. If she had been referred to as Elizabeth, then there would have been a problem.