Green’s Dictionary of Slang

a street-seller, esp. one standing on the pavement.

1849		H. Mayhew letter XV in Morn. Chron. 7 Dec. n.p.: The flying stationers are devisable into four classes—the running and the standing patterers, the long song-sellers, the song-book dealers, and the ballad singers.
1859		Hotten Dict. of Modern Sl. etc. 161: Standing patterers men who take a stand on the curb of a public thoroughfare, and deliver prepared speeches to effect a sale of any articles they have to vend.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 222/1: Some of these men become, occasionally, standing patterers, chaunters, or ballad singers.
1878		C. Hindley Life and Times of James Catnach 104: Those was the days [...] for the flying stationers and standing patterers, sir.