¶ … American foreign policy change from 1940 to the present? Before the 20th century, the U.S. had a strong tradition of isolationism and non-interventionism. Beginning with American participation in World War I and continuing with its involvement in World War II after the invasion of Pearl Harbor, the U.S. increasingly began to conceive of itself as not only a player on the international stage, but also the ideological promoter and protector of democracy. When World War II ended with the U.S. bombings of Hiroshima and Nagasaki, it was clear that America had taken a position of power in the world, both militarily and politically.

In the decade that followed World War II, American foreign policy pitted itself against Soviet Communism through the pursuit of "containment:" limiting the expansion of Soviet power and Communist ideology to other nations. This policy of containment was the primary driving force behind the "Cold War" and many of the international conflicts entered into by the U.S. In the second half of the 20th century, notably the proxy wars in Korea and Vietnam. In 1950, the United States sent troops to support South Korea, a capitalist state, who were defending themselves against attacks from the Communist North Koreans, who were in turn supported by the Chinese. In 1965, the U.S. became embroiled in a similar but more brutal conflict between the Communist North Vietnamese and the democratic South Vietnamese.

After the fall of the Soviet Union in 1991, the U.S. no longer focused on Communist containment and turned its attention to the instability in the Middle East. In the late 1970s, Jimmy Carter introduced the Carter Doctrine, which stated that military force was an appropriate tool in the defense of U.S. interests in the Persian Gulf. This doctrine was fully played out in the Persian Gulf War in the early 1990s, and again in Operation Iraqi Freedom in the early 21st century.

This policy of engaging in military action to protect our interests in the Middle East was extended after the terrorist attacks on September 11, 2001. In what has become known as the Bush doctrine, U.S. foreign policy now includes the use of preemptive strikes in stopping the spread of terrorists and terrorist ideology. This policy led to the recent wars in Afghanistan and Iraq, and to a tremendous growth in defense spending and military engagement in the last decade. Whether or not the U.S. is "winning" this war on terror is a controversial issue. Defense spending has added substantially to the growing national debt, and the waging of two simultaneous wars has stretched the armed forces to and perhaps beyond their capacity. However, the killing of Osama bin Laden and the successful withdrawal of troops from Iraq has gone far in deflating the momentum of groups like Al Qaeda and the Taliban. Whether this will be a long-term effect remains to be seen.

The changes in foreign policy over the last 70 years have had both negative and positive repercussions. On the positive side, the U.S. was able to prevent the hegemony of the Soviet Union while establishing itself as a world superpower. On the negative side, the recent policy of preemptive action has raised alarm in the international community and has potentially fostered anger in the very regions we are trying to stabilize.

Reflecting back on American history from the Civil War through the 20th century, how did life change for middle class whites, African-Americans, and immigrants?

The period following the Civil War and the Industrial Revolution in the United States has seen some of the most far-reaching advancements in human rights and quality of life in human history. Thanks to technological advancement, we are now able to travel, communicate, and access information more quickly than ever before, and advancements in medicine have all but eradicated many of the diseases that plagued earlier generations. All sections of society -- whites, African-Americans, women, and immigrants -- have experienced this progress.

After the Civil War and the industrial advancements that accompanied it, whites and African-Americans experienced a radical change in their ways of life. For whites, the introduction of factories created a strong working class but also created a need for

The economic and political growth of labor unions in the early 20th century allowed legislation like the Fair Labor Standards Act to be passed establishing a minimum wage and limiting the working day. After the substantial blow of the Great Depression, extensive economic investment in infrastructure by the Federal Government and a push to increase home ownership and retirement security led to the foundation of a vibrant white middle class in the mid-20th century. The strength of this middle class held steady through the end of the 20th century, though it has faltered in the early parts of the 21st century.
African-Americans did not have as easy a time as white Americans, but they have also seen significant improvements to their economic, political, and personal lives. The Emancipation Proclamation released them from slavery, and the 14th Amendment allowed them the same legal and political presence as their white counterparts. Racism still made social and economic advancement difficult for them in the early 20th century, especially in the Jim Crow South, but the Civil Rights movement of the 1960s went far in establishing the protection of their social and economic equality. By the end of the 20th century, African-Americans enjoyed stable political equality (culminating with the election of the first African-American president in 2008), but continued to struggle with establishing a firm foothold in the middle and upper classes, especially in urban and rural environments.

The American experience for immigrants has been volatile over the last 150 years. Despite the image of America as welcoming immigrants with open arms, their introduction to American society has often been accompanied by racial, religious, or cultural prejudice. With the flood of European refugees during the World Wars, the U.S. spent much of the 20th century learning to assimilate these new cultural influences, and by the end of the 20th century, much of the prejudice against them had subsided. However, this was replaced by a new set of tensions brought about by the influx of illegal immigrants from Central and Latin America. Combined with economic pressures, the American attitude towards Hispanic immigrants has been at times angry, and those who are illegal have been largely unprotected by the civil and economic protections afforded to citizens. However, citizen action groups have worked hard to bring their plight to light and push for reforms.

Women of all races and classes have enjoyed many of the same improvements as their male counterparts, but often at a slower pace. Women did not acquire the right to vote until the 19th Amendment was passed in 1920. Since then, they have seen an enormous advance in their political and economic presence. A large percentage of American women are now a part of the workforce, though their pay still lags behind that of men. They have also made great strides in self-determination and social expression, while still maintaining their roles as primary housekeepers and caregivers.

How did the American economy change from the industrial and market revolutions (1820s) through the Civil War (1865)?

The changes brought about by the technological and infrastructure improvements in the first half of the 19th century radically changed the face of American economics. For the first few decades after the nation's founding, the economy was dominated by regional micro economies, with each community providing for its own needs with whatever was available. However, as American territory expanded, the government put more investment into establishing a system of roads and canals to connect regions to one another. With the push into the West, a more efficient means of transportation was needed, and from 1828 through the Civil War, an extensive railway system was built connecting all of the American regions.

This burst of transportation improvement coincided with a number of technological advancement in industry. By the 1820s, the Cotton Gin, invented by Eli Whitney at the end of the 18th century, was in full use in the American South, allowing plantation owners to produce a surplus of cotton which they shipped via the new transportation system to the Northeast, whose extensive system of rivers allowed them to develop steam-powered and water-powered manufacturing plants. Agriculture in the West also experienced a major shift during this time with McCormick's invention in the 1830s of the mower-reaper. This allowed Western farmers to grow and harvest wheat much more efficiently, and to ship their surplus to the rest of the nation, providing the foundation for the "breadbasket" reputation of the Midwest.

The increased agricultural demands of the country and of the manufacturing businesses in the Northeast led to a strong demand for workers, and immigrants from many countries -- especially China and Ireland -- came to America to fill that demand. In the South, the dependence on African slaves was stronger than ever. The rights of slaves were non-existent, and the rights of immigrant workers were hardly better.

The Civil War made significant changes to the…