Very nice! It's called "chromolithography":
"J. Hoover & Sons issued popular prints for the masses in the last decade of the 19th century and the first decade of the 20th century. This was a business much like Currier & Ives, though Hoover & Sons issued chromolithographs. Joseph Hoover was one of the few native-born Americans who achieved success with chromolithography. Hoover started by making elaborate wood frames in Philadelphia in 1856, but within a decade or so he began to produce popular prints. Initially he mostly worked for other publishers, including Duval & Hunter, and he worked with noted Philadelphia artist James F. Queen. He also issued a few hand-colored, popular prints of considerable charm. During the Centennial, Hoover won a medal for excellence for his chromolithographs after Queens renderings.
In the 1880s, Hoover began to print chromolithographs, installing a complete printing plant by 1885. By the end of the century, his firm was one of the largest print publishers in the county, with an average annual production of between 600,000 to 700,000 pictures. Using chromolithography, Hoover was able to produce attractive, colorful prints that were still affordable for anyone to use as decoration for home and office. The audience for Hoover's prints was quite wide, extending through out the United States, and overseas to Canada, Mexico, England and Germany. The subjects issued by the firm are extensive, including genre scenes, still life images, views of American locations, and generic landscapes, including a series of charming winter scenes."
http://www.philaprintshop.com/chrompub.html
