Recently, the Chicago Film Archives obtained classic footage of Wrigley Field back in 1938.

Above is a film produced by Jacob Glick, a Ukrainian immigrant born in 1898, who own cigar shops around the city. His daughter, Diane Berolzheimer, and her husband donated ninety-three rolls of film to the Chicago Film Archives, and this was one of them.

This film is very historic is some capacities.

1. Back in the 1930s and '40s, there was no such thing as a batter's eye. People would sit in the view of the pitcher, catcher, hitter, and home-plate umpire. Only in the 1950s did batter's eyes come to existence. This footage features a BE-free Wrigley Field.
   
2. Back in the day, many people came to the ballpark well-dressed, and there are shots of men smoking cigars, which you'll never see in the baseball grandstands anymore.
   
3. There aren't many shots of Wrigley Field just after the ivy wall was installed in 1937. This is one such shot.
   

According to YT commentators (posted with evidence), the game was on April 22, 1938. Opening Day against the St. Louis Cardinals.

You can read more about it in this DNA Info report.