Over 100 years ago, a killer strain of the influenza virus infected over a third of the world's population.
The Gregorian calendar — used by most of the world — was introduced to fix errors in the Julian calendar mostly having to do with leap years.
On Feb. 23, 1945, six Marines raised the U.S. flag over the Japanese island of Iwo Jima. Their photo is one of the most iconic images of World War II.
One of the main risks of this rare blood disorder is internal bleeding into muscles, joints and soft tissue.
Fought on a tiny volcanic island 75 years ago, this brutal clash between American and Japanese forces defined the horror of the Pacific theater.
Megalodon was the largest shark and one of the largest fish on record. It went extinct about 2.6 million years ago.
Jerusalem is the epicenter of several of the world's major religions, but its importance is much more than just spiritual.
Anemia is a common condition that may be caused by a shortage of iron, abnormal bleeding, infections, cancer or gastrointestinal problems.
The global increase in carbon dioxide emissions is not only warming our planet at an alarming rate, but it's also making our oceans more acidic.