In common usage in the United States, they are synonyms. Wasn’t Adams acting as an attorney when he defended the British soldiers involved in the Boston Massacre?
Also, from his biography at the website of the Adams National Historical Site: “Eventually, Adams gained notoriety and became one of Boston’s most sought after attorneys.”
And a biographical sketch from the University of Virginia’s Miller Center: “By 1770, Adams was a highly successful lawyer with perhaps the largest caseload of any attorney in Boston, and he was chosen to defend the British soldiers who were charged in the Boston Massacre in March 1770.”
I had heard that Lincoln was the first Esq. POTUS, however, I’ve been searching for something resembling an original source to that effect. I do see numerous references to Adams as Esq. So, I’ll have to back off from that... I’m just trying to research all this and learn about it, especially vis-a-vis the 13th amendment(s).
Following that line, if Adams was the first POTUS with an Esq title, it would have occurred before the 13th was ratified in 1819.
I don’t know... I’m still looking. I’d like to seek out the POTUS’s after 1819 that may or may not have been Esq.