Since the turn of the century, we have amended the Constitution of the United States too often. There were only four amendments to the Constitution in the 1800s; there have been eleven amendments so far in this century.
Some of the twentieth-century amendments were passed to remedy weaknesses in the Constitution. Others, however, indicated timidity or a failure to understand the Constitution.
The Sixteenth Amendment, adopted in 1913, authorized the income tax. A good case can be made that the income tax was constitutional before the amendment was passed.
The Seventeenth Amendment, also adopted in 1913, provided for the direct election of senators. Many states were already on the way to adopting this procedure when the amendment was passed.
The Eighteenth Amendment, which took effect in 1920, was the Prohibition Amendment. It should never have been adopted, a fact recognized by its later repeal.
The Nineteenth Amendment, ratified in 1920, was the women's suffrage amendment. It should not have been needed, since the principle was already in the Constitution. But many of the states had been slow to act on the principle.
Since adoption of the Nineteenth Amendment, the states have been slow to guarantee equal rights to women in employment and other areas. This has made necessary the Equal Rights Amendment, which was proposed by Congress in 1972 and is now pending before state legislatures.
The Twentieth Amendment, adopted in 1933, corrected a few minor mistakes or omissions in the Constitution. For example, it reduced the lame-duck periods for President and Congress.