CHICAGO—The offshoot here of the anti-Wall Street protests in New York ran up against police resistance Wednesday and protesters dismantled their base outside this city's Federal Reserve Bank, but they vowed to maintain their presence on the corner indefinitely.

Occupy Chicago has been one of the largest spinoffs of the 19-day-old "Occupy Wall Street" movement, which stands against "greed and corruption" by the wealthiest 1% of the population.

Around...