The term was taken from Senator Joseph Mccarthy. During the Second red scare in the 1940s and 1950s, there was a fear in America that the soviet union somehow managed to expand their influence within United States and took control of the united states government.
Senator Joseph Mccarthy use this fear to make several accusation toward his political rivals. He accused that these rivals somehow the supporter of Communism even without having any solid proof. It's a fear mongering tactic that he used to obtain support from the people to strengthen his position within the government.
This tool is called the cotton gin. It is invented by Eli Whitney. It made the lives of the Negro slaves better by putting the harvested cotton in the machine and letting it remove the seeds than doing it by hand, which is very difficult for the slaves to do.
