Why is 1889 significant?

In the field of History, the following particular events occur:

March 4: In the United states the republican Benjamin Harrison takes possession like President of the country. April 20: Adolf Hitler born. April 22: Oklahoma City, is founded. May 31: In Pennsylvania (United States) two days of copious rain break the South Fork dam, 23 km from the city of Jhonstown. 2209 people die. October 2: In Washington DC, the 1st Pan American Conference Begins it's sessions. November 2: South Dakota and North Dakota are the 39th and 40th states of the EE. UU November 8: Montana is the 41st state of EE. UU November 11: Washington is the 42nd State of the EE. UU