On coming to St. Wenceslaus Parish last summer, Sister Barbara English thought she was entering a new world. The 53-year-old Catholic nun, a member of the Sisters of Notre Dame de Namur since 1951, had returned from 19 years of service to the poor of Maranhao, Brazil, in the northeast Amazon Basin. Now, in the upper Fells Point neighborhood of Baltimore, she was assigned to run a community center for Polish families with such names as Tomaszewski, Szcepaniak, Miksiuski and Szczach. They shopped at Ostrowski's food market, socialized at Janczak's cafe and received the sacraments at St. Wenceslaus.

The other afternoon, Sister Barbara, a woman of intelligence and compassion, said the Brazilians of the Amazon Basin and the Poles of upper Fells Point were bonded by the common enemy of outside speculators: "In Brazil, multinational and powerful national companies displace thousands of poor people in the name of progress. Here in east Baltimore, it is no different. The free market displaces those on low incomes and fixed pensions. The Polish people in this neighborhood worked for years to buy their homes."

Since January, Sister Barbara has been a leader of a citizens' group opposed to the designation of the upper Fells Point neighborhood as an historic district. Displacement is feared. Gentrifiers have already arrived, coming in with high hopes of stylized living while bringing high tax rates for the Poles who settled here in the 1900s. The Tomaszewskis and others worked the mills and factories and read their Polish newspapers. An ethnic culture has been preserved amid real estate deals that have pushed tax bills as much as 1,000 percent beyond the rates of a decade ago.

In the early 1970s, Baltimore's central business district -- less than two miles from Fells Point -- lay gasping in commercial lifelessness. Decisions were made to revive it. Federal and state money flowed in. Today's downtown Baltimore, with office buildings as towers of prosperity and an Inner Harbor at high tide with the dockside pleasures of elegant dining and shopping, is renewed.

With modernity has come history. Federal and state preservationists -- looking back on colonial times when Baltimore shone as the jewel of the Chesapeake Bay -- have designated neighborhoods as historic districts. Upper Fells Point, named after Edward Fell, who settled here in 1726, has been proposed as an area fit to be added onto the neighborhood to the south that was designated in the late 1960s.

The opposing citizens' group, organized by Polish working people and counseled by Sister Barbara, feels ambushed. For three years, a major study of upper Fells Point was being conducted without the local residents being clued in. They discovered the proposal only by accident last January. Since then, their backs to the gentrified wall, they have been trying to collect enough signatures of property owners -- 51 percent is needed by law -- to block the proposal.

Annette Sager, Polish-speaking but quickly mastering the dialect of bureaucratic English, is the president of the citizens' group. She believes that the process is backward. Referring to officials at the Maryland Historical Society, which favors the designation, she said it should be their job "to get the majority of the neighbors' signatures in favor of the proposal, not us against the designation. Their only interest is in bricks and style, not the residents and people."

The charge is denied by Rodney Little, director of the historical society. He concedes that the local citizens were not as well-informed as they had a right to be and that their suspicions have some justification. Still, he says, if the upper Fells Point neighborhood becomes an historic district -- the Interior Department is expected to decide this summer -- the goal is to "preserve not just the buildings but the community also."

If that's to happen, the struggle must rise above another pitting of the locals against the outsiders. Instead, creativity and political pressure are needed -- in sizes as large as Polish sausage links -- to get tax credits for families caught by gentrification and to resist the assaults on federal low-income housing programs.

A few years ago, the Poles thought they were protected. The Maryland General Assembly passed the Homeowners Property Tax Credit program. If a low-income person's taxes went from, say, $200 a year to $1,200, the state would cover most of the bill, depending on the income. When tax bills began going beyond $1,200, the legislature raised the credit ceiling to $1,500. Now that's not enough. Citizens in the adjacent historic district, whose houses have tripled or quadrupled in value, have been receiving tax bills well over $2,000.

One citizen who sees the futility of the two sides fighting each other is Rep. Barbara Mikulski, a lifelong resident of upper Fells Point. Her first political victory came in the late 1960s when she helped block a proposed highway through an adjacent neighborhood because it was an historic district. Now, unless protections are given to the families she lives among, Mikulski pledges to oppose the proposed expansion.

Baltimore has shown the nation how to revive a dying downtown. Its next aspiration should be to prove that a city moving up doesn't mean residents moving out.