delivery to distributors in any other
State constitutes interstate commerce, which is subject to regulation by
Congress. * * * It is no objection to the exercise of the power of
Congress that it is attended by the same incidents which attend the
exercise of the police power of a State. The authority of Congress to
regulate the prices of commodities in interstate commerce is at least as
great under the Fifth Amendment as is that of the States under the
Fourteenth to regulate the prices of commodities in intrastate
commerce."[394]

Other acts regulative of interstate commerce and communication which
belong to this period are the Federal Communications Act of 1934, which
regulates, through the Federal Communications Commission,[395]
"interstate and foreign communication by wire and radio"; the Federal
Motor Carrier Act of 1935, which, through the Interstate Commerce
Commission, governs the transportation of persons and property by motor
vehicle common carriers;[396] the Civil Aeronautics Act of 1938, enacted
for the purpose of bringing under the control of a central agency,
called "the Civil Aeronautics Authority" (functioning through the Civil
Aeronautics Administrator and the Civil Aeronautics Board) all phases of
airborne commerce, foreign and interstate.[397] None of these measures
have provoked challenge to the power of Congress to enact them.

ACTS OF CONGRESS PROTECTIVE OF LABOR ENGAGED IN INTERSTATE
TRANSPORTATION

In the course of the years 1903 to 1908 Congress enacted a series of
such measures which were notable both on account of their immediate
purpose and as marking the entry of the National Government into the
field of labor legislation. The Safety Appliance Act of 1893,[398] which
applied only to cars and locomotives engaged in moving interstate
traffic, was amended in 1903 to embrace "all trains, locomotives,
tenders, cars," etc., "used on any railway engaged in interstate
commerce * * * and to all other locomotives * * * cars," etc., "used in
connection therewith."[399] In Southern Railway Company _v._ United
States,[400] the validity of this extension of the act was challenged.
The Court sustained the measure as being within Congress's power,
saying: "* * * this is so, not because Congress possesses any power to
regulate intrastate commerce as such, but because its power to regulate
interstate commerce is plenary and competently may be exerted to secure
the safety of the persons and property transp