Uncle Tom's Cabin

From the text:

"This yer young-un business makes lots of trouble in the trade," said Haley, dolefully.

"If we could get a breed of gals that didn't care, now, for their young uns," said Marks; "tell ye, I think 't would be 'bout the greatest mod'rn improvement I knows on,"—and Marks patronized his joke by a quiet introductory sniggle.