April 17

April 17 is the 108th day of the year, and the American record for it runs from 1861 to 2014 — a span of 153 years. The entry that anchors it: The Supreme Court of the United States decides Lochner v. New York, 1905.

Through the nineteenth century the date gathered the tensions that would define the era. In 1861, the state of Virginia's secession convention votes to secede from the United States; Virginia later becomes the eighth state to join the Confederate States of America. Two years on, in 1863, Grierson's Raid begins — troops under Union Army Colonel Benjamin Grierson attack central Mississippi. A year later, in 1864, The Battle of Plymouth begins — Confederate forces attack Plymouth, North Carolina.

As the country moved into the modern age, the date accumulated new kinds of firsts. In 1905, the Supreme Court of the United States decides Lochner v. New York, which holds that the "right to free contract" is implicit in the due process clause of the Fourteenth Amendment to the United States Constitution.

In the postwar decades the date belonged to a nation of enormous reach and unfinished arguments. In 1969, Sirhan Sirhan was convicted of the assassination of U.S. senator Robert F. Kennedy. A year later, in 1970, Apollo program — the damaged Apollo 13 spacecraft returns to Earth safely.

In living memory, the date has kept adding to the record. In 2013, an ammonium nitrate explosion occurred at a fertilizer company facility in West, Texas, U.S., killing 15 people and injuring 160 others. A year later, in 2014, NASA announced the discovery of Kepler-186f, the first exoplanet with a radius similar to Earth's discovered in the habitable zone of another star.

The date is also a birthday. Among the Americans born on April 17: Samuel Chase (1741), American lawyer and jurist; Collin McKinney (1766), American surveyor, merchant, and politician; Alexander Cartwright (1820), American firefighter and (disputed) inventor of baseball; J. P. Morgan (1837), American banker and financier, founded J.P. Morgan & Co.; and William R. Day (1849), American jurist and politician, 36th United States Secretary of State.

April 17 is also a date of endings. Among the Americans who died on it: Benjamin Franklin (1790), American inventor, publisher, and politician, 6th President of Pennsylvania; Hannah Webster Foster (1840), American journalist and author; Samuel Morey (1843), American engineer; and E. G. Squier (1888), American archaeologist and journalist.

The date carries formal observance as well — Flag Day (American Samoa). Read end to end, April 17 is less a list than a cross-section: 8 entries that happen to share a square on the calendar, separated by as much as 153 years. The coincidence is arbitrary; the accumulation is not.