In February 2003, Needham, Massachusetts, became the first town in the nation to raise the minimum legal sales age for tobacco and nicotine products to 21 years (Tobacco 21). This legislation marked a dramatic departure from existing state and federal laws, which generally set the minimum sales age at 18 years. The Needham law significantly preceded and ultimately heralded the emergence of a nationwide movement to raise such sales age. As of May 2019, 14 states and more than 450 cities and counties have passed legislation raising the minimum legal sales age for tobacco and nicotine products to 21 years, covering more than 30% of the United States' population. The National Academy of Medicine projects that this policy will lower tobacco use rates, particularly among adolescents, and save a substantial number of lives. This narration of the process that led to Needham's passing of Tobacco 21 legislation and to the growth and spread of the Tobacco 21 movement highlights the significant role of public health advocacy and policy in the control of tobacco, the leading preventable cause of disease and death in the United States. (Am J Public Health. 2019;109:1540-1547. doi: 10.2105/AJPH. 2019.305209).