The term Philadelphia lawyer denotes a very able and intelligent lawyer, especially one expert in the exploitation of legal technicalities. It was originally positively connoted, but in the course of time it has come to also designate a lawyer who is clever but unscrupulous in the manipulation of the law.
This is what the U.S. dictionary Merriam-Webster explains, s.v. ‘Philadelphia lawyer’:
The reputation of the Philadelphia lawyer dates back to the colonial period, when our legal system was in its infancy and lawyers had to be especially astute. Many noted attorneys seem to have hailed from early Philadelphia, and probably no single lawyer is the source of the term, but several have been suggested. Although not strictly a lawyer, Benjamin Franklin1 is sometimes claimed to have inspired the expression through his cunning in diplomatic negotiations with the British and French. Another possible source is the Scottish-American Philadelphia attorney Andrew Hamilton2, who famously got newspaper publisher John Peter Zenger3 acquitted of libel charges in 1735, paving the way for the principle of freedom of the press in the process.
1 Benjamin Franklin (1706-90) was one of the Founding Fathers of the United States. A noted polymath, he was a leading author, printer, political theorist, politician, postmaster, scientist, musician, inventor, satirist, civic activist, statesman, and diplomat.
2 Andrew Hamilton (circa 1676-1741) was a prominent lawyer and political figure in Philadelphia.
3 John Peter Zenger (1697-1746) was a printer and journalist in New York City.
The term Philadelphia lawyer is first recorded in the phrase it would puzzle a Philadelphia lawyer and variants.
The earliest occurrence of this phrase is from Humorous Description of the Manners and Fashions of London; in a letter from a Citizen of America to his Correspondent in Philadelphia, published in The Columbian Magazine, or, Monthly Miscellany (Philadelphia, Pennsylvania) of April 1788:
The lawyers here, are surprising logicians, and Westminister-Hall [sic] has stranger paradoxes maintained in it, than any school or college, ancient or modern; for, in this, they prove right wrong, and wrong right. This Hall is said to be the largest room in England, and yet it is filled in term time with those who defend their own estate, or endeavour to get another’s. I should be glad to see the floor of this Hall, as Cato would have had the courts of law in his time, stuck with tender-hooks, to tear the feet of those who first entered to begin a law suit. They have a proverb here, which I do not know how to account for;—in speaking of a difficult point, they say, it would puzzle a Philadelphia lawyer.
The second-earliest occurrence of the phrase that I have found is both sarcastic and adapted to a particular context. It is from a polemical communication by a person signing themself ‘Fontaine’, published in the Gazette of the United States, and Philadelphia Daily Advertiser (Philadelphia, Pennsylvania) of Tuesday 3rd September 1799. The author begins by writing:
Whether the Honorable Thomas M‘Kean4, Esquire, the present Chief Justice, should be the Governor of Pennsylvania? is a question which has been mooted by the distinguished Orator of causes, Reporter of adjudications, and Secretary of the Commonwealth, Alexander James Dallas5, Esquire, and others his associates.
‘Fontaine’ then wonders “whether a political navigator, who is to govern the vessel of state, should be a good helmsman or a good weathercock”. He remarks that, “as respects the main question now pending about a governor”, the main objection against Chief Justice McKean is “the consideration of his being a notorious weathercock in the political world”. He then writes:
This, then, is a difficulty which might puzzle almost any of the Philadelphia lawyers who have only such common minds as Tilghman6 or Rawle7. But the big mind of Dallas is different from theirs. He says, the weathercock is the very thing. Let him, therefore, point out its use for the ship!
4 The lawyer and politician Thomas McKean (1734-1817) was Chief Justice of Pennsylvania from 1777 to 1799. He became Governor of Pennsylvania in December 1799.
5 Alexander James Dallas (1759-1817) was Reporter of Decisions of the United States Supreme Court from 1790 to 1800, and Secretary of the Commonwealth of Pennsylvania from 1791 to 1801.
6 Edward Tilghman (1750-1815) was a prominent lawyer in Philadelphia.
7 William Rawle (1759-1836) was a prominent lawyer in Philadelphia.
The phrase occurs in the opening lines of an article published in The Balance, and Columbian Repository (Hudson, New York) of Tuesday 15th November 1803—the jurist and statesman Edward Livingston (1764-1836) had been removed from the offices of Attorney of the United States for the district of New York and of Mayor of New York City:
It would (to use a Yankee phrase) puzzle a dozen Philadelphia lawyers, to unriddle the conduct of the democrats towards that great ornament of their party, Edward Livingston, Esq.
The earliest instance that I have found of Philadelphia lawyer as an independent term is from a letter “to the Freemen of Vermont”, by a person signing themself ‘Mentor’, published in the Vermont Courier (Rutland, Vermont) of Saturday 26th August 1809:
The first administration had every inducement to administer the government agreeable to the principles of the Constitution, but the new managers, who had gained their offices by representing that course of measures to be wrong, were forced to take different ground to keep up the delusion, and keep themselves in favor. Instead of measures of importance being originated upon the floor of Congress and being there debated in a frank, open and manly style, with a regard to the constitution and the general good, a secret, unconstitutional, irresponsible, and irresistable [sic] faction was formed to feel the public pulse and dictate to the government the course of measures to be pursued. As they evidently sought to flatter and please rather than serve the people, the President instead of meeting Congress like his predecessors, and frankly giving his opinion on the state of the Union, must send them a Message, loaded with projects and alternatives, dressed in the language of a political wizzard [sic], (which a philadelphia [sic] Lawyer could not understand.) and communicate his secret wishes by the back stair and water-closet Members of Congress.