When Thomas Jefferson asserted that a constitution should change every 19 to 20 years, he was expressing a deep-rooted conviction that governments need to adapt to survive. Although he did not personally participate in drafting the U.S. Constitution, he had strong opinions about what political leaders had to do in order to make it work.

Thomas Jefferson's Letter to Samuel Kercheval

In an 1816 letter to Virginia lawyer Samuel Kercheval on the subject of calling a convention to revise the state's constitution, Jefferson stated that a constitution should be revised every 19 to 20 years. Jefferson's proposed time period was based on the era's mortality rate. Since a majority of adults at any point in time would likely be dead in approximately 19 years, he reasoned, a new generation should have the right to adapt its government to changing circumstances instead of being ruled by the past.

The 20-Year Rebellion

Jefferson's belief in the importance of periodic political change was not limited to state constitutions. For example, in 1787, while he was away serving as the country's ambassador to France, Jefferson wrote a letter to John Adams' assistant discussing the national Constitutional Convention. In this letter, Jefferson mentioned Shays' Rebellion, an armed protest in Massachusetts, and wrote, "god forbid we should ever be twenty years without such a rebellion." However, Jefferson did not regard violent conflict as intrinsically necessary. In a letter written shortly before his death in 1824, Jefferson stated that the U.S. Constitution could last perpetually if it were regularly amended to reflect new developments in science and society.