The Overland Campaign was a massive and sustained offensive General U.S. Grant designed to draw the Army of Northern Virginia to battle in defense of Richmond.  A series of battles were fought on this design, including the Wilderness and Cold Harbor.  Casualties were very heavy but Grant wore down Lee and achieved the strategic success of crossing the James River and besieging Petersburg.  (By John Osborne)  

A structural defect, said to be caused years before in faulty installation of new boilers, caused several of the walls of the Female Insane Department of the Blockley Almshouse in Philadelphia suddenly to collapse. Dozens of inmates were buried in the rubble. Fifteen died and more than twenty more were seriously injured.  (By John Osborne)   

The Grand Central Sanitary Fair, combined to represent the states of Pennsylvania, New Jersey, and Delaware, was opened officially in a ceremony at its 540 foot long temporary main structure built across Logan Square highlighting the more than a mile of building front in the city.  The Fair ran till June 27, 1864 and collected more than one and a half million dollars to support the work of the Sanitary Commission.  (By John Osborne)   

Soon after the news of the great confrontation in Virginia filtered into the city, the first trainloads of wounded began to arrive in the city.  Five hundred were received this day, and four days later, on the 15th, more than a thousand arrived, followed by another nine-hundred and seventy-eight on May 18, 1864. More than 2,100 others arrived in the last week in May, making a grand total for less than three weeks of more than five thousand. (By John Osborne)   

The boiler-house of Cornelius and Baker, a gas-fitting establishment at Eighth and Cherry Street in Philadelphia, was completely destroyed when its main boiler blew up at around seven thirty in the morning.  The explosion killed six men at work at the building and a large section of the boiler flew through the air and killed another man on Eleventh Street, three blocks away.  Another section came down through the roof of the William Penn Tavern on Filbert Street, killing a horse and injuring a stablehand.  (By John Osborne)   

The newly formed 56th Massachusetts Infantry, under their 22 year-old Colonel Stephen Minot Weld, were passing through Philadelphia on the way to Virginia.  When one soldier was found drunk, Weld ordered the nearby tavern ransacked, its liquor destroyed, and its owner, Henry Brown, arrested.  Weld took Brown with him to Baltimore in handcuffs where the Provost Marshal ordered his release, but not before Weld had had "half his head and beard shaved."  (By John Osborne)