Given the team and dates on the marquee in this photo, it wasn’t too difficult to find.
Wait, what? A scheduled series of five single games? Why did they do that? We don’t see things like that in modern baseball and I don’t recall any series like this in my time going to Wrigley Field.
While I don’t have a definitive answer to this question, I have an educated guess.
1958 was the first year the major leagues had teams on the West Coast. The Dodgers and Giants moved to Los Angeles and San Francisco, respectively, from back east for the 1958 season. Before 1958, with both leagues having no teams west of St. Louis or south of Washington, all travel was done by train. This resulted in very long road trips and homestands. You can see that, for example, in the Cubs’ 1957 schedule. Look at it beginning near the end of May. The Cubs went on a 20-game (!) road trip, followed by a 20-game homestand.
Obviously, with two clubs now both more than 1,800 miles from their nearest competitor, air travel was going to have to begin to become necessary. In the Cubs’ 1958 schedule, then, you see a West Coast trip — with an off day on either side — followed by that five-game series against the Braves at Wrigley. The Braves’ 1958 schedule, meanwhile, shows them on the road in a very strange pattern starting in late April — two games at Philadelphia, one at Pittsburgh, two at Cincinnati, then home for one series, then traveling to Chicago and St. Louis.
This was likely due to train schedules. While teams now travel on charter flights, back then they had to book travel on regularly scheduled trains. This was the case for early air travel for teams, too; in 1966, the Cubs and Astros agreed to suspend the second game of a doubleheader August 11 at 5:30 p.m. because both teams had to catch a scheduled flight to the West Coast for a game the next day. That game was eventually completed in Houston.
The Cubs wound up winning three of those five games, going into first place over the then-defending World Series champion Braves. Two of the three wins were on walkoff homers — Johnny Goryl on May 1 and Walt “Moose” Moryn on May 2. The Cubs and Braves played two other three-game series at Wrigley Field in 1958, for the then-normal total of 11 games at one park, but didn’t face each other there after July 20.
We see five-game series in baseball occasionally now. They usually happen when a postponed game is made up during an already-scheduled four-game series. The Cubs had one of those against the Cardinals in July 2018.
But five-game series like the one on the marquee above? Those went out with the quaintness of teams traveling by train.