In 1857, C. W. Richmond and H. F. Vallette described the small Illinois community of Cottage Hill:

The village of Cottage Hill is pleasantly situated on the line of the Galena and Chicago Union Railroad, sixteen miles west from Chicago. The first settler here was J. L. Hovey, who came from Painesville, Ohio. He built a small house in 1843, which he kept as a hotel, it being favorably known by the farmers of the Fox and Rock river counties, who then teamed their own produce to Chicago, as the ‘Hill Cottage.’ The ‘Hill’ proper lies half a mile from the railroad, and commands as fine a prospect of prairie, cultivated farms, groves, cottages, and railroad trains, as one could desire to behold. This place being but 15 1-2 miles from the centre of business in Chicago; having good water, pure air, and railroad trains hourly passing – all of which stop here – must soon become known to those who would find for themselves and families, at a convenient distance from the city, a retreat from the noise and dust of its hot and crowded streets. (194)
This sounds like a suburb. A beautiful natural setting. Railroad access to Chicago. A small community. Away from the hustle and bustle of the big city.
However, at the time of the description, Cottage Hill (later Elmhurst) had very few people. The 1870 Census counted 329 residents. The train line offers access to Chicago but it is less than a decade old at this point. Commuting to Chicago is limited.
Elmhurst today is quite different. It has over 46,000 residents and the median household income is over $149,000. There is little open land on which to build. There is still greenery – laws, trees, parks – and road and train access to Chicago.
What this suggests to me is that long before the mass suburbanization of the twentieth century (Elmhurst had the highest percentage population increase in the 1920s), Americans had a suburban ideal. Even in the 1850s these two writers had a sense of the contrast between Cottage Hill and Chicago. They may not have envisioned the suburbs looking like they do today but some of the key elements are there long before suburban populations swelled.