Lowell, once the textile capital of the world, grew in the shadow of the huge mills lining the Merrimack River. Its ancient canals earned the city the nickname "Venice of America." With the southward movement of the textile industry in the 1920s, Lowell sought to diversify its economy to include a variety of manufactured products. By 1984, however, the town's economy had become as dependent on the mini-computer as it had formerly been on cotton. The early mill days are commemorated in the city's splendidly preserved industrial architecture. Lowell, whose downtown has been designated an urban national historical park, exists today as a living reminder of the processes and consequences of the Industrial Revolution.