The term "Philadelphia lawyer" came about in 1735. A Philadelphia lawyer by the name of Andrew Hamilton, acting pro bono (i.e., without charging legal fees), traveled to defend the fledgling newspaper New York Weekly Journal in a freedom-of-the-press case. The owner of the paper, John Peter Zenger, was sued for libel by William Crosby, the colonial governor, because of criticisms he had published in his paper. Hamilton won a complete acquittal on the grounds that the criticisms offered were statements of fact. A great deal of attention was called at that time to the fact that it took a "Philadelphia lawyer" to win a case in New York.
Woody Guthrie popularized the term in 1937 with his song "Reno Blues," the lyrics of which go . . .
Where romance blooms and fades,
A great Philadelphia lawyer
Was in love with a Hollywood maid.
"Come, love, and we will wander
Down where the lights are bright.
I'll win you a divorce from your husband,
And we can get married tonight."
Wild Bill was a gun-totin' cowboy,
Ten notches were carved in his gun.
And all the boys around Reno
Left Wild Bill's maiden alone.
One night when he was returning
From ridin' the range in the cold,
He dreamed of his Hollywood sweetheart,
Her love was as lasting as gold.
As he drew near her window,
A shadow he saw on the shade;
'Twas the great Philadelphia lawyer
Makin' love to Bill's Hollywood maid.
The night was as still as the desert,
The moon hangin' high overhead.
Bill listened awhile to the lawyer,
He could hear ev'ry word that he said:
"Your hands are so pretty and lovely,
Your form's so rare and divine.
Come go with me to the city
And leave this wild cowboy behind."
Now back in old Pennsylvania,
Among those beautiful pines,
There's one less Philadelphia lawyer
In old Philadelphia tonight.
This song was also recorded by Merle Haggard and Willie Nelson.