Lawrence, Massachusetts is like that.
Lawrence was built originally as a mill city by factory owners for their workers and mills in the early 1840s. The city its self encompasses an area that was divvied up between the nearby towns of Methuen, Andover, and North Andover, and divided today into two main parts which are divided by the Merrimack River. The original city is called North Lawrence, while the are on the south side of the Merrimack is South Lawrence.
South Side became much more prosperous with better homes and even gained the main railroad station, today's only station, while North Lawrence retained the mills and the downtown. Today it's all poor, but if one were to live in Lawrence, they would choose South Lawrence over North Lawrence.
As I type this, I think of my own city of Haverhill, which is located downstream on the same river. Haverhill is one of the oldest cities in the US, being founded in the 1630s, and was built as a manufacturing center which initially made bricks from clay out of the Little River, a small tributary to the Merrimack, and then manufactured shoes until that all moved to Brazil and Asia in the 1970s. While Haverhill was the manufacturing center, a close neighboring town of Bradford, also named after a town in England, was more genteel with farms and big estates, though there were some apartments and a few factories. The most of the people in Bradford worked and shopped in Haverhill, but commuted across the bridges home to Bradford, thus, making the two towns enjoined right from the beginning. In the 1880s, Bradford merged with Haverhill as by that time they were sharing water, gas, and sewer services, however, even today Bradford maintains that distinction of being the "better" area with more tree lines streets, a college campus (a defunct college now), a pretty square, and still lots of open space.
When I build my cities, I try to maintain the same look. Instead of making one continuously paved city from one end of the map to another, I have small towns, usually with a railroad station, and I establish a downtown of sorts with suburban houses and eventually farms and woods. This separates the towns up, and even on the 81-tiles we now have access to with that famous mod, that makes a whole lot of difference in how my cities look and perform.
.png){kind=avatar}
