Congress has received roughly 11,985 proposals to amend the Constitution since 1789. Exactly 27 have been ratified. That's a 0.2% success rate.
Each amendment needs two-thirds approval in both the House and Senate, then ratification by three-quarters of state legislatures. Congress has endorsed 33 amendments total. Six passed Congress but failed at the state level. The Equal Rights Amendment, guaranteeing equal rights regardless of sex, passed Congress in 1972 with a 1979 deadline. Congress extended the deadline to 1982. It still fell three states short. Nevada, Illinois, and Virginia ratified it decades later—in 2017, 2018, and 2020—but courts and lawmakers dispute whether those late ratifications count.