In 1916, President Woodrow Wilson established June 14 as Flag Day, to commemorate the 1777 adoption of the “Stars and Stripes” as the national flag of the United States. Flag Day had been celebrated unofficially prior to 1916, as you can see in the first photo below. I recently gathered images from the collections of the Prints and Photographs Division for inclusion in a Flickr album featuring flags, which inspired me to expand my search and mark the occasion of Flag Day. The images shown here are all retrieved in a search in the Prints and Photographs Online Catalog (PPOC) using the search term “flag day.” The first two photos date to earlier Flag Day celebrations: Post Ofc. Dept. Flag…