March 7: Clean Monday (Gregorian calendar, 2011);Teachers’ Day in Albania; Casimir Pulaski Day in Illinois (2011)
- 161 – Following the death of Roman Emperor Antoninus Pius, Marcus Aureliusand Lucius Verus agreed to become co-Emperors in an unprecedented arrangement in the Roman Empire.
- 1850 – In support of the Compromise of 1850, United States Senator Daniel Webster gave his “Seventh of March” speech, which was so unpopular among his constituency he was forced to resign.
- 1871 – José Paranhos, Viscount of Rio Branco(pictured), became Prime Minister of the Empire of Brazil, starting a four-year rule, the longest in the state’s history.
- 1914 – Prussian William of Wied began his short reign as sovereign prince of the newly independent state of Albania.
- 2009 – The Kepler space observatory, designed to discover Earth-like planets orbiting other stars, was launched.