What legislation made it a crime to interfere with the military's efforts during World War I?

The Espionage and Sedition Acts were significant pieces of legislation passed during World War I, aimed at suppressing dissent and maintaining national security. The Espionage Act of 1917 made it a crime to interfere with military operations or recruitment, as well as to support the nation's enemies. The Sedition Act of 1918 further expanded the scope of the Espionage Act by making it illegal to speak out against the government, the Constitution, or the military efforts of the United States.

These acts were enacted in a climate of heightened nationalism and fear during the war, reflecting the government's attempt to control public opinion and stifle opposition, particularly from socialist and anti-war activists. The effects were far-reaching, contributing to a culture of suspicion and limiting the freedom of expression during a critical period in American history.

In contrast, the other options do not directly address the criminalization of interference with military efforts. The Selective Service Act was primarily concerned with conscription, while the Military Draft Act focused on mandatory service rather than on suppressing dissent related to military efforts. Thus, the Espionage and Sedition Acts directly pertain to the criminalization of interference with military operations during World War I.