Tuberculosis campaign, early 20th century. Doctor using a stethoscope to check a boy's lungs for signs of the respiratory bacterial disease tuberculosis (TB). The doctor is being aided by nurses from what is now known as the American Lung Association (then called the National Tuberculosis Association). Their hats include the distinctive logo of their association, which was founded in 1904 to campaign against tuberculosis. Efforts to reduce the millions affected by TB included an annual Christmas Seal Campaign, and another centred on the 'Spirit of the Double Barred Cross'. This modified Cross of Lorraine became the official anti-TB symbol in 1920.