A Bernado says, in England (and the American colonies) the Gregorian calendar was introduced in 1752, and Wednesday, September 2, 1752 was immediately followed by Thursday, September 14, 1752. This traumatic change resulted in widespread riots and the populace demanding "Give us the eleven days back!" So, there was no 7th September that year. I'm not surprised you cannot find anything of note that happened that day.
The 2nd September is remembered because in 490BC the Athenian runner Pheidippides left the town of Marathon for the city of Sparta to seek help against the invading Persian army. Despite not being able to recruit any allies, the Athenians defeated the Persians. Pheidippides then ran to Athens to carry the news of the victory, an event that later marked the beginning of modern marathons. A yearly race from Marathon to Athens commemorates Pheidippides's feat.
However, the 14th September is noted (by some) as the day in 1741 when George Frederick Handel finished "The Messiah" having worked nonstop for 24 days, living on coffee. His manuscript is now in a British Museum case with a draft of Paul McCartney's "Yesterday". Also, in 1812 it is the day Napoleon occupied Moscow. In 1849 Ivan Pavlov was born, his salivating dogs lead to the principle of conditioning (rings a bell with me!), and in 1959 the Soviet Lunik II became the first spacecraft to land on the Moon. It touched down at 0730 GMT in Palus Putredinis.