Gary, Indiana was a prosperous industrial city before the Great War of 2077. Located on the south shores of Lake Michigan, just east of Chicago, the city's economy was dependent on the American steel industry. As a result of the Sino-American war, factories were operating at full capacity, and the city flourished. However, the heavy industry that had brought so much to the city would also be its downfall, and on October 23, 2077, a Chinese nuclear warhead was detonated over the downtown area, destroying much of the infrastructure, and killing thousands, save for the lucky few that had secured a spot in the vault underneath city hall.
The ruins of the city lay dormant for nearly 30 years, save for the occasional band of raiders or nomadic tribes making their way to or from Chicago. In 2107, the vault opened, and the families within began to make their ways out into the wasteland. One of the vault dwellers, Karl Stahlmann (A German immigrant and railroad worker before the bombs fell) soon took charge of the survivors, and the rebuilding of the city. In 2112, he led an expedition along Lake Michigan, where they soon discovered the ruins of the Windy City to the west. Through careful diplomacy, an agreement was reached between the mob families of Chicago and Stahlmann - Chicago would provide electricity to Gary in exchange for steel from the Gary mills, and the signing of a non-aggression pact. After it was discovered that transporting the steel to Chicago via Brahmin was too troublesome, Stahlmann ordered that the railroad lines between the two cities be rebuilt. When Karl finally passed away in his sleep in 2139, rail traffic between the two cities averaged almost two-hundred trains per day.