(Recasts with Fed's listening tour in two cities; adds quotes from Harker, details; dateline previously Philadelphia)

By Trevor Hunnicutt

CAMDEN, N.J./PHILADELPHIA, May 17 (Reuters) - Two top Federal Reserve officials went to Camden, New Jersey, on Friday, taking a different reading of the pulse of the U.S. economy by visiting what is by one measure the country's lowest-income city, as the central bank seeks advice on how to do a better job.

Patrick Harker, president of the Philadelphia Fed, and Federal Reserve Vice Chair Richard Clarida spent the morning in Camden, which squats in the shadows of Philadelphia's downtown skyscrapers but has the lowest median household income among U.S. cities.

The dichotomy of Philadelphia's gleaming office buildings and destitute people on the streets of nearby Camden underlines the limits of Fed policy, even as most policymakers see the central bank's dual mandate of price stability and maximum employment as having been met.

In July, the U.S. economy will celebrate 10 years of expansion, the longest on record.

Yet at events in Camden and Philadelphia, the policymakers heard that while some progress is being made linking employers and workers, many Americans continue to struggle.

"What drives the racial wealth gap is income and the fact that for the last 50 years we've had crisis-level unemployment in certain demographics," said Omar Woodard, executive director at GreenLight Philadelphia, a group focused on alleviating poverty, speaking on one of the Fed's panels.

Camden's population is 45 percent African-American, according to the U.S. Census Bureau.

Unemployment numbers draw out the divide across the country. Black U.S. unemployment stands at 6.7%, far higher than the more than 49-year low overall for Americans of 3.6%.

WHAT'S LIMITING GROWTH?

Friday's events were the latest in a series of "Fed Listens" events that Clarida held around the country while the Fed considers whether to change its approach, for instance by keeping interest rates lower for longer to boost inflation expectations - something that might help drive growth.

It is unclear how directly the policy review will answer criticisms that the Fed has raised interest rates too much. President Donald Trump has repeatedly lambasted the Fed for raising rates, saying that it is holding back growth. The Fed, after hiking rates four times in 2018, has put any further rate increases on hold so far this year.

The Fed took extraordinary steps, including buying bonds, to support the economy in response to the 2007-2009 financial crisis, but it has been criticized both for doing too much and too little.