To many, Framingham might seem like an odd choice for such an important study, instead of a better-known and more populated metropolis, like New York City or Boston. The city was actually selected as the site before researchers determined that this would be an epidemiological study — meaning one that looks at the history of the disease and its effect on people over time.
Ideally, the study would have been established in geographically separate areas at the same time, to represent a wide variety of racial, socioeconomic and regionally impacted groups. "The Framingham investigators have always been aware that the site may not be representative of the United States and have made repeatedly comparisons with other regions to test its generalizability," the scientists note on the study's website.
At the time the FHS started, the Framingham population of 28,000 was a mostly white and middle-class. However, the town did have some things going for it as a research site. The population was large enough to supply participants, yet the town was physically small enough that it wasn't too hard to observe or check in with them. The medical community and local hospitals were also very supportive of the study. The town had previously participated in the Framingham Tuberculosis Demonstration, so reseachers were pretty well assured cooperation from the locals [sources: Framingham Heart Study, Whitney].
Although not ideally diverse in nature, there were other ethnic groups represented in Framingham, thanks to an influx of post-World War II residents. This trend has only increased since the study's inception, with Framingham now home to about 70,000 residents [source: CityTownInfo].
Once the researchers had a location, they had to figure out how to enlist enough participants.