114 
COMMERCIAL GEOGRAPHY 
belong the highlands of Maine, the White Mountains, the 
Green Mountains, and the Berkshires of New England, the 
Adirondacks and the Highlands of the Hudson. Southward 
they include the Blue Ridge and the long parallel ranges that 
reach from eastern Pennsylvania to central Alabama. West of 
these mountains is the Appalachian plateau, more familiarly 
known as the Catskills in New York, the Allegheny uplands 
in Pennsylvania, and the Cumberland plateau in Kentucky and 
Tennessee, and reaching out toward the Mississippi River in 
Ohio and Indiana. 
These heights are crossed by important valleys, of which the 
following have the greater commercial value: the Hudson- 
Champlain in New York and Vermont; the Hudson-Mohawk 
in New York ; the Susquehanna in Pennsylvania ; and the Poto- 
mac in Maryland and Virginia. To meet the more southern of 
these openings the Ohio and its branches reach into the highlands 
from the west. By way of these gaps the earliest railways and 
canals in America were laid out, and here to-day are found the 
New York Central, Pennsylvania, and Baltimore and Ohio rail- 
way systems. These passes likewise have determined the posi- 
tion of New York, Philadelphia, and Baltimore, and will, through 
all time, contribute to their growth and sustain their trade. 
Throughout most of the length of the Appalachians runs a 
broad valley, fertile in soil, rich in towns, and serving as a great 
highway. Parts of this great Appalachian valley are known as 
the middle Hudson valley in New York, the Cumberland valley 
in Pennsylvania, the valley of Virginia, and the valley of East 
Tennessee. Among its towns are Reading, Harrisburg, Hagers- 
town, Staunton, Knoxville, Chattanooga, and Birmingham. 
The Appalachians have forests of pine, spruce, and hard 
woods, offer fertile valleys running among the heights, are 
abundant in water power, are rich in iron and coal, and hold 
these resources within easy grasp of the great commercial 
centers and smaller industrial cities of the Atlantic lowlands. 
86. Mississippi Basin. Unlike as they look on the map, 
North America and Europe resemble each other in structure