In 1950, Milwaukee was the 15th-largest American city, Indianapolis was 23rd and both were considered nondescript, second-tier localities. Into the 1960s, both cities were aging, with declining Rust Belt economies. Locals knowingly referred to Indianapolis as "India-no-place."
However, in the '60s, while open housing and school integration marches were taking place in Milwaukee, Indianapolis civic leaders were actively researching legislation that might revitalize their city. In 1967, Republicans won the governor's office, both houses of the legislature, the Indianapolis mayor's office, the Indianapolis City Council, the Marion County Council and promptly passed a very contentious piece of legislation that consolidated Indianapolis with its surrounding county.
Beyond the fiscal benefits, Indianapolis was instantly America's 11th-largest city. Suburbanites who had turned their backs on the city or sniped at it became supporters of what they then viewed as "their" notable metropolis. The enlarged community of political and civic leaders sublimated partisanship and leveraged this newfound pride to undertake a successful campaign to position Indianapolis as the national and international signature city for amateur sports. The city's image skyrocketed, and, man, so has its economy.
Emphasis added. An easy way for a city to get bigger is to expand the municipal boundaries. Pittsburgh should be so lucky. Speaking of Pittsburgh, The Urbanophile recently posted about Don Carter's TEDxPittsburgh talk. The arresting visual demonstrates the sprawl. Yes, Pittsburgh has a sprawl problem. Population problem? Not really. The metro population today is the same as it was in 1950. Pittsburgh isn't dying!
On the other hand, Braddock is dying. The reasons for Braddock's demise are commonly misunderstood. I've misunderstood the decline. I'll make you do the work and click through to one of Chris Briem's (Null Space) posts about Braddock. What's killing Braddock? Sprawl. People working at the still functioning steel mill now have a nice piece of suburbia. The bulk of the former residents didn't pick up and move to the Sun Belt. We need a better definition of Rust Belt city.