Article II, Section 3 of the U.S. Constitution grants the president the power to convene a special session of Congress on "extraordinary occasions." As of October 2013, there have been 27 special sessions of Congress called by the President of the United States. The first was in March, 1797, in which John Adams convened Congress to ask Congress to suspend relations with France. The most recent was in July, 1948, in which President Truman convened Congress to consider civil rights legislation.

Extraordinary Occasions

The term "extraordinary occasions" is not defined in the Constitution, but Justice Joseph Story, who was a founder of Harvard Law School and a Supreme Court Justice in the early 19th century, spelled out several situations in which it would be appropriate for a president to call a special session of Congress in his "Commentaries on the Constitution of the United States." These include dealing with foreign aggression or hostilities, unexpected disasters and insurrection.

Amendment XX

In 1933, the passage of the 20th Amendment to the Constitution made changes to the times that Congress convenes that have eliminated the need for most special sessions. There have been only four special sessions called since the 20th Amendment was ratified. Three of these had to do with domestic legislation, and one was called by President Franklin D. Roosevelt in 1939 to declare neutrality in World War II.