Largely thanks to the efforts of Robert M. La Follette, Congress in 1915 enacted the Seamen's Act, providing the merchant marine with rights similar to those gained by factory workers. This law had been prompted by the sinking of the Titanic in 1912, a disaster that had clearly illustrated the lack of planning and concern exhibited by the major shipping companies. The Seamen's Act was regarded as the "Magna Charta of the seas" and mandated the following:

• Limited working hours for 56 per week (9-hour days)
• Guaranteed minimum standards of cleanliness and safety
• Established the ability of seamen to sue for damages against negligent ship owners
• Established the right of crews to draw half pay while in port
• Recognized the right of seamen to organize.

At the time of this measure's passage, the United States had not entered World War I. However, the U.S. merchant marine used its neutral position to assume the dominant position in the world carrying trade. Much attention was paid to conditions endured by seamen and La Follette, always the champion of the underdog, responded.