Gibbons v. Ogden cleared the way for Congress and the federal government to control interstate commerce. An example of interstate commerce is

Example-cattle crossing a state line while grazing and the movement of pollutants across state lines have been cosidered interstate commerce.

interest groups send representatives to state capitals and to washington, d.c. to put pressure on members of congress and other policymakers. they engage in lobbying, or the organized process of influencing legislation or policy. lobbying can take many forms. interest groups can testify in congressional hearings.