Answer:
No hablo español muy bien, pero lo intenté. ¡espero que esto ayude!
Entre 1868 y mediados del siglo XX, Japón había creado un enorme imperio que se extendía desde Alaska hasta Singapur.
(Between 1868 and the middle of the 20th century, Japan had created a huge empire that stretched from Alaska to Singapore.)
They use a system called "Checks and Balances".
The goal of the transcontinental railroad was to connect the eastern part of the United States to the western part. Both the Central Pacific and the Union Pacific Railroad companies worked to build this long railroad. Some positive effects of the transcontinental railroad included more efficient transportation from coast to coast, a faster spreading of ideas throughout the United States, and increases in global and intercontinental trade. A negative effect of the transcontinental railroad was that racial tensions among Native Americans and other groups arose.
The event shown is the atomic bomb being dropped on the Japanese city of Nagasaki in 1945