January 1 - This Day in History

45 BC - Julius Caesar's Julian calendar takes effect, with the start of the year January 1¹
1801 AD - The United Kingdom of Great Britain and Ireland formed²
1808 AD - US Congress bans the importation of slaves from Africa³
1852 AD - John George Children, a British Chemist dies⁴
1899 AD - Spanish rule in Cuba ends⁵
1912 AD - Several provinces declare independence from China and Sun Yatsen as the first Provisional President of China⁶
1937 AD - In Britain, safety glass becomes mandatory in vehicle windshields⁷
1947 AD - The Canadian Citizenship Act 1946 comes into effect, changing British citizens to Canadian⁸
1954 AD - NBC makes the first coast-to-coast NTSC color broadcast⁹
1965 AD - The People’s Democratic Party of Afghanistan founded¹⁰
1971 AD - Cigarette commercials on US television banned¹¹
1989 AD - The Montreal Protocol to regulate chemicals that deplete the ozone layer comes into effect¹²
1999 AD - The Euro introduced as an accounting currency¹³
2007 AD - Leon Davidson, a chemical engineer and scientist who worked on the atomic bomb dies¹⁴

[1] "Julian calendar | History & Difference from ... - Britannica." https://www.britannica.com/science/Julian-calendar. Accessed 2 Dec. 2019.

[2] "History of Ireland (1801–1923) - Wikipedia." https://en.wikipedia.org/wiki/History_of_Ireland_(1801%E2%80%931923). Accessed 2 Dec. 2019.

[3] "Congress abolishes the African slave trade - HISTORY." 9 Feb. 2010, https://www.history.com/this-day-in-history/congress-abolishes-the-african-slave-trade. Accessed 2 Dec. 2019.

[4] "John George Children (1777–1852) | The Embryo Project ...." 25 Mar. 2018, https://embryo.asu.edu/pages/john-george-children-1777-1852. Accessed 2 Dec. 2019.

[5] "When did Spanish rule in Cuba end." https://www.answers.com/Q/When_did_Spanish_rule_in_Cuba_end. Accessed 2 Dec. 2019.

[6] "Republic of China (1912-1949) - Totally History." http://totallyhistory.com/the-republic-of-china-1912-1949/. Accessed 2 Dec. 2019.

[7] "1937 in the United Kingdom - Wikipedia." https://en.wikipedia.org/wiki/1937_in_the_United_Kingdom. Accessed 2 Dec. 2019.

[8] "Canadian Citizenship | The Canadian Encyclopedia." https://www.thecanadianencyclopedia.ca/en/article/citizenship. Accessed 2 Dec. 2019.

[9] "NTSC - Doctor HDMI." http://www.drhdmi.eu/dictionary/ntsc.html. Accessed 2 Dec. 2019.

[10] "People's Democratic Party of Afghanistan | Military Wiki ...." https://military.wikia.org/wiki/People%27s_Democratic_Party_of_Afghanistan. Accessed 2 Dec. 2019.

[11] "History of Tobacco Regulation - The Ban on ... - Drug Library." http://www.druglibrary.org/schaffer/library/studies/nc/nc2b_10.htm. Accessed 2 Dec. 2019.

[12] "Montreal Protocol | international treaty | Britannica." https://www.britannica.com/event/Montreal-Protocol. Accessed 2 Dec. 2019.

[13] "History of Euro." http://www.euro-dollar-currency.com/europic/history_of_euro.htm. Accessed 2 Dec. 2019.

[14] "Leon Davidson - Wikipedia." https://en.wikipedia.org/wiki/Leon_Davidson. Accessed 2 Dec. 2019.