The document discusses the history and development of railroads and airlines in the United States. It describes how railroads became the primary mode of long-distance transportation in the late 1800s after the completion of the first transcontinental railroad in 1869. It also discusses how airlines grew to replace railroads as the main transportation method over long distances in the 20th century following the Wright brothers' first flight in 1903. The document further analyzes the business practices of each industry, including the use of trusts and pools by railroads to reduce competition and regional airlines now facing consolidation pressures from larger carriers.