Subscribe to This Day in History

Discover events in American history – plus the stamps that make them come alive.

Today’s Article

  • #3428 2006 63c Distinguished Americans: Dr. Jonas Salk
    March 26, 2026

    National Science Appreciation Day
    On March 26, 1953, Dr. Jonas Salk announced the first successful polio vaccine, offering hope against one of the most feared diseases of the 20th century. That moment now anchors National Science Appreciation Day, a modern observance that highlights how careful research and tested discoveries can change lives.
    Read More