You know that Wrigley Field's look has been mostly the same since the current brick-and-ivy-walled bleachers were completed late in 1937. Despite being rebuilt in 2005 and being currently under construction with videoboards being added, the basic "look and sweep" (as the Landmark Commission calls it) of the bleachers has remained the same for more than 75 years.
The Chicago Film Archives has unearthed this terrific film from the early days of the current configuration of Wrigley:
The date given by the Film Archives at the beginning of the YouTube video says 1937, but the film's YouTube page says 1938, and given the shot of the scoreboard shown at the end of the film, it was clearly taken April 22, 1938, as all the scores on the board match the games that were played that day (six games; two were rained out).
That makes perfect sense, as April 22, 1938 was the date of the home opener at Wrigley Field that year. The team marching in, in unison, from the outfield would have made sense on that day. The Cubs blew a 5-2 lead in the ninth inning and lost 6-5 to the Cardinals that afternoon (interestingly enough, former Cub Guy Bush pitched the final inning for St. Louis), but they had the last laugh in 1938: they won the National League pennant.
You'll also notice also the clear look at a sign on the building at the corner of Waveland & Kenmore that says "RICKETTS." That was advertising a restaurant that was on Clark Street about a mile south of Wrigley Field from the 1920s through the mid-1960s. Here's a photo essay I did on that sign back in 2009.
This is very cool film. Enjoy!