The group of names “Tom, Dick, and Harry” signifying any indiscriminate collection of masculine representatives of hoi polloi was a more or less haphazard choice.
It probably started with names common in the sixteenth century.
Thus Sir David Lyndesay, in Ane Dialog betwix Experience and ane Courteour (c. 1555), has, “Wherefore to colliers, carters and cokes to lack (Jack) and Tom my rime shall be directed.”
And Shakespeare, in Love’s Labour’s Lost (1588), gives us in the closing song, “And Dicke the Shepheard blowes his nails; and Tom beares Logges into the hall.”
And “Dick, Tom, and Jack” served through the seventeenth century. But our present group was apparently an American selection.
It appeared (according to George L. Kittredge’s The Old Farmer and His Almanac, 1904) in The Farmer’s Almanack for 1815: “So he hired Tom, Dick and Harry, and at it they went.”