The $50 Series I savings bond certificate features Helen Keller. Here is the official Fifty Dollar I Bond description from the U.S. Treasury:

Helen Keller (1880-1968) lost her sight and hearing as a young child due to illness, but overcame these challenges and went on to become the twentieth century's best known advocate for people with disabilities. Through her writing, lectures, and work with various organizations, Keller focused public attention on issues affecting the handicapped. She was also successful in making Braille the standard for printed communication with the blind. She had a lifelong relationship with the American Foundation for the Blind, and was instrumental in the Lions Club International's devotion to the blind and blindness prevention.

More About the Series I Savings Bond

You can read our Guide to Investing in Series I Savings Bonds. This will walk you through tons of information about savings bonds, especially the series I savings bond, including how you can add them to your portfolio, annual purchase limits, ownership requirements, tax benefits, and much more.