Maybe because cars were not invented at the time, or cars were invented, but they were too expensive for most people. (You didn't really specify what time period.)
The Civilian Conservation Corps (created in 1933) was a government program that helped to employ millions of young American men between the ages of 18-25 to work on environmental projects all over the United States. This agency, created by FDR's New Deal, helped to plant billions of trees all across the US while helping to decrease the unemployment rate during America's Great Depression. Besides planting trees, this agency helped to create trails and organize many of the state parks we use today.
Skyscrapers were built to conserve space
