According to the history page of American Red Cross, the organization began in 1882. In the 23 years following that, the organization aided in disaster relief efforts with the US Army during the Spanish American War. Not until prior to WW1 was the first water safety, first aid and health program introduced by the organization, where they first expanded their efforts and scope of what they can offer. What truly motivated the way and thinking of disaster relief was the outbreak of war America had. The organization grew tremendously because of war. In the 4 years between 1914 an 1918, chapters of American Red Cross went from 107 to 3,864- which is astonishing. Membership also grew from 17,000 to 20 million in that time. With this large jump of people and chapters came a large growth in funding and material to cover programs, hospitals, nurses, etc to aid refugees and American and Allied forces. Then in 1918, influenza pandemic struck and American Red Cross was able to help combat that and in the process took on more nurses to do so. This trend of growth is seen during times of war, or devastation such as the Great Depression, Mississippi River flood and WW2. Ultimately, what motivated the growth and disaster response was the need for it. As need increased for care during times of war, devastation or disease, American Red Cross grew, due to those in support of troops overseas, volunteering time and money, which allowed for the organization to grow and gain the moment needed to combat epidemics and eventually natural disasters.
Website with an excellent (and brief) explanation of fair use to copyrighted materials, along with a useful fair-use checklist that can be used to assist in fair-use analysis.