William James Sidis died of a cerebral hemorrhage in Boston at the age of 46.

William James Sidis received a patent for a rotary perpetual calendar that took into account leap years.

William James Sidis was arrested for participating in a socialist May Day parade in Boston that turned violent. He was later sentenced to 18 months in prison under the Sedition Act of 1918.

William James Sidis graduated from Harvard University with a Bachelor of Arts degree, cum laude, at the age of 16. He earned a mixture of A, B, and C grades during his time at Harvard.

William James Sidis was born in Boston, Massachusetts, to Jewish emigrants from the Russian Empire (now Ukraine). His father, Boris Sidis, was a psychiatrist and polyglot, and his mother, Sarah (Mandelbaum) Sidis, was a physician. William was named after his godfather, Boris's friend and colleague, the American philosopher William James.