This clip shows the hearing with McCarthy and Joseph Welch, head counsel for the US Army. It contains the famous and often quoted statement "Have you no decency, sir?"
Notes about Joseph McCarthy
Joseph McCarthy was a US Senator from Wisconsin starting in 1947. He tried for years to accuse people of being Communist during the worst part of the "Red Scare" of the early 1950s. The term "McCarthyism" is used today to describe the practice of accusing people without proper evidence to back it up.