May 18, 1980 - Mount St. Helens erupts in southwestern Washington State.
May 18, 1920 - Karol Josef Wojtyla (Pope John Paul II) is born near Warsaw, Poland.
May 18, 1896 - SCOTUS rules "separate but equal" in the case of Plessy v. Ferguson.
May 18, 1860 - Abraham Lincoln was nominated for President at eh Republican Convention.