The events happened on 24th May are :
: Opening of the Baltimore and Ohio Railroad : The Baltimore and Ohio Railroad was the first steam-operated railway in the United States to be chartered as a common carrier of freight and passengers. The first 21 km (13 miles) of line opened this day, spanning from Baltimore to Ellicott's Mills (now Ellicott City), Maryland. The maiden voyage of Peter Cooper's locomotive Tom Thumb demonstrated to doubters that steam traction was feasible on the steep, winding grades. The B&O Railroad Company was established by Baltimore merchants to compete with New York merchants and their newly opened Erie Canal for the trade to the West.
: In the U.S. nuclear program, the fourth test of Operation Greenhouse resulted in the first proof-of-principle test of a booster design in nuclear fission. Boosting referred to a process whereby thermonuclear reactions were used as a source of neutrons for inducing fissions at a much higher rate than could be achieved with neutrons from fission chain reactions alone.
: Irish author William Trevor was born in County Cork, Ireland.
: John Brown led an antislavery party to murder five men from a proslavery settlement on Pottawatomie Creek in Kansas Territory in the Pottawatomie Massacre.
: Part of the Latin American wars of independence from Spanish rule, the Battle of Pichincha took place on the lower slopes of Cerro Pichincha, an Andean volcano; it was a victory for South American rebels.
: The Toleration Act was passed by the British Parliament, granting freedom of worship to Nonconformists and allowing them their own places of worship and their own teachers and preachers.
23rd May | 25th May