By 1850 , the Galena and Chicago Union Railroad ( after that , the Chicago & Northwestern and now Union Pacific ) was constructed as far as Elgin , Illinois , and passed through the settlement area . In the 1850s the land on which Oak Park sits was part of the new Chicago suburb , the town of Cicero . The population of the area boomed during the 1870s , with Chicago residents resettling in Cicero following the Great Chicago Fire of 1871 and the expansion of railroads and street cars to the area . " In 1872 , when Oak Park received its own railroad depot on the Chicago and Northwestern Railway , its rapid emergence as a residential suburb of Chicago began . In 1877 , the railroad was running thirty-nine trains daily between Oak Park and Chicago ; in the subsequent year , more railroads and street car lines , with increased service , came to link Oak Park and Chicago . As Chicago grew from a regional center to a national metropolis Oak Park expanded – from 500 residents in 1872 to 1,812 in 1890 , to 9,353 in 1900 , to 20,911 in 1910 , to 39,585 in 1920 . Oak Park thus emerged as a leading Chicago suburb . " A review of Oak Park 's history by Wiss , Janny , Elstner Associates in 2006 further explains the importance of railroads and street cars in the development of Oak Park : The Village of Oak Park was formally established in 1902 , disengaging from Cicero following a referendum . According to the local historical society , " The period 1892 – 1950 saw the construction of almost all of the housing stock in Oak Park , and most of the village 's current buildings . " The village population grew quickly , and " by 1930 , the village had a population of 64,000 , even larger than the current population " , while cherishing a reputation as the " World 's Largest Village . " Chicago grew rapidly in the 19th century , recording 4,470 residing in the 1840 Census in the place so recently a fur trading post , reaching 1,099,850 in 1890 , and then 1,698,575 in 1900 , passing Philadelphia to the number two spot in the US , and in that year , the fifth largest in the world . Chicago was well located on the shores of Lake Michigan for transport ; after the fire of 1871 , Chicago rebuilt its center and exploded with new ideas ; Oak Park grew along with its neighbor to the east , having location and railroad and street car connections in its favor
Great Chicago Fire
Great Chicago Fire
Oak Park, Illinois