Final answer:
The McCarthy Trials ended when Senator Joseph McCarthy directed his accusations of Communism against the US military, leading to the televised Army-McCarthy Hearings and his subsequent censure by the U.S. Senate in 1954.
Step-by-step explanation:
The McCarthy Trials ended when Senator Joseph McCarthy directed his accusations of Communism against the US military. This culminated in the Army-McCarthy Hearings of 1954, where McCarthy's methods of intimidation and doubtful accusations were publicly exposed to the American audience through televised sessions. The most definitive blow to McCarthy's campaign came when he accused a young Army officer of communism, prompting the Army's chief counsel, Joseph Welch, to famously question his sense of decency. Later in 1954, the U.S. Senate censured McCarthy for his conduct, effectively ending his influence and political career.