Growing up in Jenkintown in the 1970s, Kate Pettit could easily cross Old York Road, from her mother's fabric store to a friend's house, on foot.

Those days, however, are gone. Mom-and-pop shops like her mother's have been replaced by big-box retailers. And Jenkintown's main street has turned into a traffic-clogged artery better known as Route 611.

"A customer was in here just this morning saying she felt like she lived in the city," said Pettit, who manages a toy store in downtown Jenkintown.

A changing Jenkintown, along with other parts of Philadelphia's suburbs, is reflected in data released Tuesday as part of the U.S. Census' American Community Survey.

The data - an aggregation of information spanning 2005 to 2009 - paints a portrait of the region that is at times ho-hum and at others surprising:

By and large, the rich got richer or held their own since the 2000 census; the poor mostly got poorer. And in the solidly middle-class townships along 611's northern stretch, median household income suffered.

According to the data:

Many of the more affluent suburbs grew more so. Chester County's Birmingham Township maintained its distinction of having the highest median household income ($163,929) of the 238 municipalities in Bucks, Chester, Delaware and Montgomery Counties. As a whole, Chester County boroughs and townships held eight of the top 10 spots in the ranking, and most grew in wealth.

Delaware County's poorest municipalities continued to show declines in income levels compared with 2000. Chester City - with a median income of $25,000 - maintained its position on the bottom of the list. Clifton Heights, Darby, and Collingdale also saw declines. All also showed an increase in poverty.

Large population centers like Lower Merion (median household income of $112,100), and Newtown Township, Bucks County ($104,763), held steady compared with 2000 or exhibited slight gains.

But along 611, many municipalities saw an undeniable decline. Cheltenham slipped 10 percent in median household income - from about $79,443 in 2000 to $71,516 in the latest data, with numbers adjusted for inflation. Jenkintown saw a similar drop-off from 2000's $61,459 to $55,723. Abington fared better, declining only 3 percent.

Those numbers don't necessarily mean that residents are earning less, said Michael J. Swavola, who has served on Cheltenham's Board of Commissioners for nearly two decades.

Instead, they may reflect a new type of resident in the boroughs and townships along the corridor, he said - largely younger, in earlier stages of their careers and more closely tied to Philadelphia's urban life, he said.

"We're getting new and young families in our area that may not be as socioeconomically elevated as the people we had before," he said.

Some of people who first came to the area seeking refuge from city life have moved further out, he said.

Still, the effects of the recession can't be ignored. Joseph M. Hoeffel III, a Montgomery County commissioner and chairman of the Delaware Valley Regional Planning Commission, argued that middle-class families have taken some of the hardest hits.

"The recession has been with us for three years, now," he said. "It's hurt at all income levels - but it has hurt people unequally."

For Pettit, who owned a bridal business before turning her Jenkintown storefront into toy shop, that has meant adapting to meet both her customers' income levels and their stage in life.

"I was sewing their wedding gowns five years ago," she said. "Now I'm selling their children their first toys."

Contact staff writer Jeremy Roebuck at 610-313-8212 or jroebuck@phillynews.com.