Manufacturing Regions of the United States 255 
men, of all nationalities, work at the great blast furnaces where iron ore is smelted to make pig 
mills where the steel is rolled out into rods and plates for further use in industry. 
the automobile began to be important, and the industry naturally 
came to have a center. Detroit was no better adapted to be such a 
center than several other cities; but when once it had become the 
automobile city, it grew so fast that it is more than twice as large as 
Milwaukee, and is one of the world’s greatest cities. 
In the southern part of the middle-western manufacturing district, 
Cincinnati is the largest of a group of cities which includes Indianapo- 
is, Columbus, and Dayton. These cities lie some distance from the 
ron-ore route of the Great Lakes, but are supplied with cheap coal 
either by way of the Ohio River or from local coal fields. Consequently 
they do not engage largely in the manufacture of the heavier kinds of 
ron goods, such as steel rails and steel cars, but specialize in articles 
ike typewriters, cash registers, and automobile ignition apparatus, 
articles in which the amount of iron is small in proportion to the work 
put into the product. Slaughtering, meat packing, and the accom- 
panying occupations, such as soap making, are also important, because 
many animals are raised on the surrounding farms; but the bulk of 
the animals produced farther west go to Chicago and St. Louis. 
Manufacturing in the Northeastern Section 
outside of the Three Districts 
There is a large part of the northeastern section of the United 
States that is in marked contrast to the area of concentrated manu- 
facturing. 
Where manufacturing is extensive and simple. In the North At- 
lantic district, the Central New York district, and the Middle West 
district, manufacturing is infensive,; that is, the region is well covered 
with manufacturing cities. Many of them are large, and their indus- 
trial plants are on a great scale. The type of manufacturing is also