Many Philadelphia boosters proudly boast of its reputation as a rough-and-tumble city. Soften those edges with a look at its history of silk production.

The culture of silkworms (Bombyx mori) began in China nearly five millennia ago with the discovery that caterpillars' cocoons could be unwound to lustrous effect. Its roots in the New World were established with the first permanent English settlement, Jamestown. The colony's phlegmatic namesake, James I, hoped to discourage settlers' tobacco farming by sending mulberry trees and silkworm eggs in 1623. (Silkworms feast on mulberry leaves.) A statute fining those who did not dedicate a certain percentage of their fields to mulberry trees added encouragement.

In 1725, Pennsylvania statesman James Logan, wrote to the Penn family explaining that "the culture of silk in [the colonies] is extremely beneficial and encouraging." Silk production, or sericulture, loomed in the public's mind after Benjamin Franklin and the American Philosophical Society began a subscription to establish a filature of raw silk in city limits.

Before the Revolution, nearly 2,300 pounds of cocoons were brought to reel in Philadelphia. Farther afield in the commonwealth, a Lancaster County woman, Susanna Wright, crafted a silk dress worn by the queen of Britain at court. The oncoming war, however, mothballed the nascent industry.

In the early 1800s, raising silkworms locally inched upward in popularity. Philadelphia physician Philip Syng Physick became a plush supporter after building a filature called "The Cocoonery" in the city's Germantown neighborhood. Silk societies soon sprouted in several states, with books extolling the profession's virtues.

The Silk Growers Almanac, published in 1848, listed no fewer than 22 reasons why U.S. farmers should raise mulberry trees and silkworms. No. 18: "Because a man, with a little land, who has a family, can increase his mulberry trees and keep his family employed at home, without the risk of sending them abroad for employment, where they would be liable to have their morals corrupted."

After the Civil War, with technological innovation shifting most production from the hand-twisting homestead to the steam-powered factory, nearly 100 companies were engaged in the manufacture of silk goods in Philadelphia. The silken roster included ribbons, curtains, upholstered goods, gimps, webbing, fringes, tassels, military regalia, flags, undertaker supplies, muff girdles, and - despite Philadelphia's reputation as a rough city - silk underwear.

By 1900, one-third of America's silk textiles were manufactured in Pennsylvania, mostly in Philadelphia, Scranton, and Allentown.