Calvin Coolidge became the 30th president of the United States after Warren G. Harding suffered a fatal heart attack.

Calvin Coolidge was the 30th president of the United States, serving from 1923 to 1929. A Republican lawyer from Massachusetts, he previously served as the 29th vice president from 1921 to 1923 under President Warren G. Harding, and as the 48th governor of Massachusetts from 1919 to 1921. Coolidge gained a reputation as a small-government conservative with a taciturn personality and dry sense of humor that earned him the nickname "Silent Cal".

The president of the United States (POTUS) is the head of state and head of government of the United States. The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces.

Warren Gamaliel Harding was the 29th president of the United States, serving from 1921 until his death in 1923. A member of the Republican Party, he was one of the most popular sitting U.S. presidents while in office. After his death, a number of scandals were exposed, including Teapot Dome, as well as an extramarital affair with Nan Britton, which damaged his reputation.

A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction to the heart muscle. The most common symptom is retrosternal chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn. This is the dangerous type of acute coronary syndrome.