Sept. 23 (UPI) -- On this date in history:
In 1806, U.S. explorers Meriwether Lewis and William Clark returned to St. Louis on their historic journey from the Mississippi River to the Pacific Coast and back.
In 1846, German astronomer Johann Gottfried Galle discovered the planet Neptune at the Berlin Observatory. Neptune generally is the eighth planet from the sun.
In 1909, Gaston Leroux's Phantom of the Opera was published.
In 1950, the U.S. Congress adopted the Internal Security Act, which provided for the registration of communists. It was later ruled unconstitutional by the Supreme Court.
In 1959, Soviet Premier Nikita Khrushchev visited the corn fields of Iowa to find out what made the American farmer tick and urged that the earth "be furrowed by plows, not rockets and tanks."
In 1966, a Rolling Stones' concert at England's Royal Albert concert hall was halted temporarily when screaming girls attacked Mick Jagger onstage. The riotous enthusiasm of the fans resulted in a ban of pop concerts at the hall.
In 1973, Juan Peron was again elected president of Argentina after 18 years in exile. His second wife, Isabel, who became vice president, and succeeded him after he died 10 months later.
In 1991, 44 U.N. inspectors were detained in Baghdad after attempting to remove secret Iraqi plans for building nuclear weapons. They were freed five days later.
In 2005, a fire killed 23 people on a bus carrying Texas nursing home evacuees from Hurricane Rita.
In 2008, a 22-year-old student killed 11 adult students and himself at a vocational college in Finland 205 miles north of Helsinki.
In 2010, the U.S. Congress enacted the Small Business Jobs and Credit Act, a multibillion-dollar package of tax breaks and government loans to aid small businesses. President Barack Obama signed the bill into law four days later.
In 2014, U.S. President Barack Obama, speaking at a U.N. Climate Summit, warned of the "urgent and growing threat of climate change." Obama said countries such as the United States and China must lead the way in efforts to reduce pollution. "We have a responsibility to lead," Obama said. "That's what big nations have to do."