Commodore Perry carried a letter from the president of the US.
Natural boundaries are an easy way to mark a barrier. It’s easier than having to build something like a wall and it is likely to be known by other empires. Natural boundaries can also be more durable. Mountains can often be used and they are difficult to travel through so the empire could have just been prevented by the boundary.
The term informal empire describes the spheres of influence which a polity may develop that translate into a degree of influence over a region or country, which is not a formal colony, protectorate, tributary or vassal state of empire, as a result of its commercial, strategic or military interests.
The seating arrangement on this southern bus reflects changes started by the ruling in Brown v. Board of Education. In the image we can see both White and African-American people using the same bus. It's even possible to watch a young African-American girl seated next to a white woman.
Case Brown v. Board of Education is a landmark judicial ruling by the United States Supreme Court that declared state laws that established separate schools for African-American and white students denied equality of educational opportunities.
The ruling was delivered on May 17, 1954, unanimously (9-0) by the Warren Court; and established that "separate educational facilities are inherently unequal". With this, the Supreme Court reversed the existing precedents from Plessy against Ferguson in 1896. As a result of this ruling, racial segregation came to be considered as a violation of the Equal Protection Clause of the Fourteenth Amendment to the United States Constitution. This ruling opened the way for racial integration and achieving civil rights for African Americans.