The Constitution is amended because times change.
As new things happen, you have to update the foundation.
Like slavery and women's rights, the founding fathers couldn't set anything protecting women's rights or abolishing slavery because of the time they lived in.
constitution
an alteration or addition to a constitution
A revision of, or addition to, a constitution
Amendment
An amendment
amendments.
the addition of amendments to the constitution by congress
They wanted protections against tyranny of the central government.
An Amendment.
amendment
cheese
amendment