Law Encyclopedia: Esq.
This entry contains information applicable to United States law only.
An abbreviation for esquire, which is a title used by attorneys in the United States. The term esquire has a different meaning in English law. It is used to signify a title of dignity, which ranks above gentleman and directly below knight.
In the United States, Esq. is written after a lawyer’s name, for example: John Smith, Esq.
so writing esquire after one’s name would be like me signing my name “Mr KMS61.”
How many lawyers have you run across that actually use Esq.? I've probably run across a couple in the last 25 years.