Births on September 30

Thomas W. Lamont, American banker and philanthropist (d. 1948)

Thomas William Lamont, Jr. (September 30, 1870 – February 2, 1948) was an American banker.

15 Jan

Thomas Nast
A political cartoon for the first time symbolizes the Democratic Party with a donkey ("A Live Jackass Kicking a Dead Lion" by Thomas Nast for Harper's Weekly).
30 Mar

Reconstruction Era
Texas is readmitted to the Union following Reconstruction.
12 May

Royal Assent
The Manitoba Act is given the Royal Assent, paving the way for Manitoba to become a province of Canada on July 15.
18 Jul

Papal infallibility
The First Vatican Council decrees the dogma of papal infallibility.
19 Sep

Siege of Paris (1870-71)
Franco-Prussian War: The Siege of Paris begins, which will result on January 28, 1871 in the surrender of Paris and a decisive Prussian victory.