Lithographs made it possible for Salesmen to sell their products. What is a lithograph, you ask, originally printers found that with a grease pencil or crayon the printer could mark the limestone. The process then continued with rolling the ink on the stone and pressing the paper to it for a print. What was particularly helpful for these printers is that the stone could be used over and over again making as many prints as the printer wanted. It didn't take long before the stones were exchanged for metal plates.
What did this mean for the 19th century? Many things. As previously mentioned yesterday salesmen had copies of their product to sell in picture form. Currier & Ives begin in 1835 as did many other printers. It opened yet another business for mankind, one that only a handful of people had been able to do before. It allowed artists to get their work out. Illustrators were used in newspapers and on and on it went.
As the century developed so did the techniques. At first the lithographs were black and white and the artist would paint the color to the prints. By the 1880's advertising had blossomed and so did the printing base, allowing color to be printed. There were a lot of changes in the printing industry during the 19th century, just as there has been a lot in our own century.
What this all means for us who write historical fiction, think creatively, look at all the occupations that come just from the invention of the lithograph. There is the printer, the business man who owns the printing business, the artists who painted in the black and white prints and the artist who prepared the printing plates for the prints.