Union membership remained constant, airplanes were used for carrying mail, and urban sprawl was driven by the automobile in the 1920s.
Union Membership in the 1920s: During the 1920s, union membership remained constant, as depicted by the decline in the labor movement primarily due to factors like the influx of immigrants, language barriers, and exclusion of certain groups.
First Practical Peacetime Use of Airplanes: The first practical peacetime use of airplanes was for carrying mail, highlighting the crucial role of airplanes in enhancing communication and transportation.
Urban Sprawl in the 1920s: The main factor causing urban sprawl in the 1920s was the automobile, demonstrating how the expansion of automobile usage influenced urban development.
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