The borough of Slatington was incorporated in 1864, but settlement on the site dates back to the eighteenth century.
This watercolor appeared in an auction at Cowan's Auction. Here is the catalog description:
American, watercolor on paper. A bird's eye view of the Lehigh Gap, in present day Slatington, Pennsylvania. Location sited and dated Lehigh Gap, July 25th, 1846 lower right; 10" high x 16.25" wide (sight).