Philadelphia Print Shop co-owner and Antiques Road Show regular Christopher W. Lane will return to Chestnut Hill on Wednesday, Sept. 10, for a presentation on the American West.

The presentation will take place at Chestnut Hill branch of the Free Library of Philadelphia between 7:30 and 9 p.m.

At the beginning of the 19th century, the United States was limited to lands east of the Mississippi River. The vast region which today is the country’s trans-Mississippi West was at that time divided into French Louisiana, northern New Spain, and a somewhat ­ disputed British Columbia District.

By the end of the century, these would all be part of the United States, divided into 23 political states and territories. The story of the changing political configuration of the trans-Mississippi West between 1800 and 1900 is a complex and fascinating one and this lecture will tell that tale, illustrated by contemporary maps.

In 1982, Lane and Donald H. Cresswell founded the Philadelphia Print Shop in Chestnut Hill, selling antique maps and prints. In over 30 years, Lane has authored books and myriad articles, as well as given lectures around the country. Cresswell and Lane have also been the map and print experts for the Antiques Roadshow for the last 18 years.

In 2010, Chris’s wife got a job in Denver, Col., so Lane opened a branch of his shop there, The Philadelphia Print Shop West. Naturally specializing in Western material, Lane has done extensive research in the development of the American West and prints and maps showing that. This lecture provides an overall picture of that development as reflected in period maps.