"Interstate commerce, in U.S. constitutional law, any commercial transactions or traffic that cross state boundaries or that involve more than one state."
https://www.britannica.com/topic/interstate-commerce-United-States-law
"The Interstate Commerce Clause is a provision that is included in the United States Constitution and is formally known as the Commerce Clause."
https://constitution.laws.com/american-history/constitution/interstate-commerce-clause
"In the early 1800's, the precise definition of interstate commerce was not critical, because national markets had not developed and intrastate commerce was regulated only lightly by the American state governments."
http://encyclopedia.federalism.org/index.php/Interstate_Commerce
"In 1887, Congress passed the Interstate Commerce Act, making the railroads the first industry subject to federal regulation."
https://www.pbs.org/wgbh/americanexperience/features/streamliners-commerce/
"The Interstate Commerce Act was passed by Congress on February 4, 1887 to address the cost of freight-shipping on the railroads. The Interstate Commerce Act created an Interstate Commerce Commission to oversee the conduct of the railroad industry."
http://m.american-historama.org/1881-1913-maturation-era/interstate-commerce-act.htm
"Interstate Commerce Commission (ICC), former independent agency of the U.S. government, established in 1887; it was charged with regulating the economics and services of specified carriers engaged in transportation between states. Surface transportation under the ICC's jurisdiction included railroads, trucking companies, bus lines, freight forwarders, water carriers, oil pipelines, transportation brokers, and express agencies."
https://www.infoplease.com/encyclopedia/history/north-america/us-government/interstate-commerce-commission
"The Commerce Clause of the U.S. Constitution prohibits state laws that unduly restrict interstate commerce under a well-established doctrine created by the U.S. Supreme Court and known as the dormant commerce clause."
https://mjbizdaily.com/how-interstate-commerce-could-upend-the-marijuana-industry/amp/
"Because of the Commerce Clause, regulating interstate commerce falls to the federal government, not the states."
https://spectator.org/silly-rabbit-the-internet-is-interstate-commerce/