It was common practice for these solo performers to use an accent, a costume, and peculiar (but identifiable to the audience) mannerisms or movements on stage. The best had several personas or 'characters' and could switch from one to another. Their fake (not native to them) accents often were very good; the result of study and practice.
The "Artful Dodger," reproduced above from a broadside, is one-dimensional; it lacks the actions and persona of the performer, and the little asides and interaction with the audience mentioned by Joybell. References to events are no longer topical. We look at the words and think that it didn't take much to amuse an audience in those days. The broadsides we have of the "Dodger" or "Billy Barlow," judging from the few comments that have been preserved from people who saw performances by a good actor like Cowell, are little more than shadows of the real thing.
Sketches by artists such as Cruikshank, showing these performers in their stage personas help a little, but the only way we can evaluate them now is through the performances of the few who have brought this kind of artistry into the 20th century.
   
Red Skelton's skits would be equally flat if all we had to go by were the words of the script. Bette Midler did a solo on the New York stage, using several personas. One of the greats was Cornelia Otis Skinner. A genius like Chaplin could do it all without words; luckily he chose films or he would be almost unknown to us today.