Today is Friday, April 12, the 103rd day of 2024. There are 263 days left in the year. Today’s Highlight in History: On April 12, 1955, the Salk vaccine against polio was declared safe and effective. On this date: In 1861, the U.S. Civil War began as Confederate forces opened fire on Fort Sumter in South Carolina. In 1945, President Franklin D. Roosevelt died of a cerebral hemorrhage in Warm Springs, Georgia, at age 63; he was succeeded by Vice President Harry S. Truman. In 1955, the Salk vaccine against polio was declared safe and effective. In 1961, Soviet cosmonaut...