I guess Horner Park isn't a building per se, but I was lurking through the 1913 Illinois Sanborn Insurance Maps and saw that the big area at Irving Park and California wasn't a park. It was a brickyard.
In 1902, the Lake View Brick Company, which had offices at Ashland and Diversey, purchased property at Irving Park and California. The brick company shows up on a 1905 insurance map below.
They bought more land after 1905. Their empire grows more vast in the map below from 1913. The majority of the land was clay pits. Berteau also went all the way through the park, although with the river there, it doesn't go very far.
Brick was all the rage since the wood got a bad rap in 1871, but those clay pits didn't last forever. Eventually, the pits were exhausted and the plant shut down around 1936. What was vogue at the time was to throw garbage into the pits until they were full and then pave plant or pave over them. Considering how large those pits were, they were being used as garbage dumps for 11 years before the neighborhood got tired of the smell and the unsightly grounds. In 1947, the alderman of the 40th Ward at the time, Benjamin Becker, and some of his predecessors, managed to condemn the brick company's buildings and seize the land for a park.
In this insurance map from 1949, you can see the company marked as "not in operation." Some of the buildings had been demolished by the time of the map's publication.
It took a while, but eventually in 1955, they had all of the land from Irving Park to Montrose along California. They proposed a fieldhouse with two gymnasiums and a pool.
From the same Trib article: "First floor of the building which contains approximately 40,000 square feet, will house two gymnasiums, offices, reception center, storage rooms, a club room, a physical exercise room, and a gym gear room.
A kitchen and six clubrooms will be located on the second floor. The basement features a large hall for games, locker room, craftshops, and a second kitchen.
Interior walls of the fieldhouse will be of glazed tile, and the entire building will be soundproof. Terra cotta will be used in the main corridor."
The Horner Park fieldhouse was completed in November 1956. Soon after, it was used for all sorts of music and theater, sports, crafts, community meetings, and many other gatherings.
In 1958, they finally moved the statue of Henry Horner to the park.
Today, Horner Park underwent another facelift to remove invasive plant species and to restore a natural grass habitat along its southern edge. While this park has had a bad rap in the past, the recent upkeep has helped bring it back into focus as a neighborhood gathering place.