Thursday, May 5, 2022 Business Lamar Advertising Company acquires Burkhart Advertising By Julia-Claire Evans - May 5, 2022 FacebookTwitterLinkedinEmailPrint Lamar Advertising, which has called Baton Rouge home for more than 100 years, is the nation’s largest outside advertising company. (Tim Mueller) Baton Rouge-based Lamar Advertising Company today announced it has acquired Indiana-based Burkhart Advertising. Already an INSIDER? Sign in.