Before the Civil War, Philadelphia was a center of

Before the Civil War, Philadelphia was a center of  shipyards and manufacturing.

Explanation:

At the beginning of the 19th century, Philadelphia experienced an important economic growth thanks to its agricultural and mining wealth; the construction of routes, canals and railroads allowed the city to maintain its privileged position in the industrial revolution. The textile industry, the confection, the metallurgy, the manufacture of paper and of railway material, the naval construction in the shipyards and the agricultural industry were the main industries of the 19th century. Philadelphia was at the same time a financial center of prime importance. During the Civil War, the factories of the city supplied the armies of the Union.