The Eastern Roman Empire, or Byzantium, managed to survive much longer then the Western Roman Empire because of multiple factors.
Some of the most important factors are that Byzantium had a strong leadership. The hierarchy was well placed, and the policies of the empire were good and prosperous.
Also, Byzantium was very wealthy, controlled important trade roots, had very well developed agriculture, and produced lot of goods, thus making the empire economically strong.
The military was well payed, well equipped, well organized, and it was loyal to the crown.
Approximately 180 million years
All continents were united in one super continent known as Pangaea. according to Wegener, an observation into the shape and designs of the continents reveals that all the continents were once one large mass. the continent begun to split approximately 180,000 million years ago.
U.S. Bureau of Refugees, Freedmen , and Abandoned Lands was established by Congress to provide practical aid to 4,000,000 newly freed Black Americans in their transition from slavery to freedom.
Founded by Abraham Lincoln.
Abraham Lincoln is my answer