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The United States，with its highly diversified and technologically advanced industrial sector，is by far the important manufacturing country in the world.The largest U.S.manufacturing industries today are chemicals，industrial machinery，electronic equipment，food processing，motor vehicles，fabricated metal products，and printing and publishing.

The chemical industry employs over one million people and manufactures almost 26％ of the world’s total chemical products.Most of the basic chemical industries are concentrated along the Gulf Coast，while Texas and Tennessee are leading centers of more advanced chemical manufacturing.

Transportation equipment has always been a very important industry in the United States.Since automobiles are typically necessities of American life，they play a central role in the nation’s economy.The automotive industry also has great influence on other industries：the major consumer of steel，plastics，rubber，glass and other basic materials.It generates jobs across a wide swath of the economy beyond the transportation industry proper.Most automobiles are produced in the region around the Great Lakes.The state of Michigan is the leading producer of automobiles，with the city of Detroit serving as home to the headquarters of the“Big Three”major auto manufacturers：General Motors，Ford Motor Company and Chrysler Corporation.

The state of Washington is the center of the U.S.aircraft manufacturing industry，as it is the site of most of Boeing’s production facilities.These include the Boeing Everett Factory south of Seattle，which is the largest building（and factory）in the world by volume at 13.4 million cubic meters.

Electronic and electric equipment is one of the fastest growing U.S.manufacturing sectors.The United States leads the world in the development and production of computer software.In the production of computer equipment，microprocessors and semiconductors，the United States ranks second in the world.The computer and software industries are centered in California’s Silicon Valley，south of San Francisco，which is home to the headquarters of companies such as Apple Computer and Google.

U.S.industries are unevenly distributed throughout the nation.Traditionally，most of the nation’s manufacturing industries have been concentrated in the northeastern part of the country and in the Midwest along the southern shores of the Great Lakes.Today，there is increasing growth of manufacturing centers outside the Midwest and Northeast.In particular，the South has developed into a significant industrial region.Tennessee，Mississippi，Alabama and South Carolina now account for over a quarter of U.S.automobile manufacturing.Many modern textile companies have moved their production from New England to southern states，and today，about 90％ of the U.S.textile industry is located in the South.

Another change in U.S.industry is its internationalization.Large corporations began a wave of international partnerships in the late 1990s.Some companies became multinational corporations through merging with foreign companies.In recent years，most major industries have developed their business abroad;they not only sell products in other countries，but also establish manufacturing facilities and administrative headquarters in other countries in order to cut costs.