Since 1789, congress has sent 33 constitutional amendments to the states for ratification. Of these, 27 have been ratified.
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The opium wars ended with China losing money and a colony.
Brown v. Board of Education (1954). The case ruled that segregated public schools were unconstitutional on the grounds that "separate could never be equal." The case overturned Plessy v. Ferguson, a landmark and deeply racist Supreme Court decision from 1896 that had allowed segregated education.
C. 250 years (I believe )