Understand
The United States is not the America of television and movies. It is large, complex, and diverse, with distinct regional identities. Due to the distances involved, traveling between regions can be time-consuming and expensive.
Culture
The United States is made up of many diverse ethnic groups and the culture varies greatly across the vast area of the country and even within cities - a city like New York will have dozens, if not hundreds, of different ethnicities represented within a neighborhood. Despite this difference, there exists a strong sense of national identity and certain predominant cultural traits. Generally, Americans tend to believe strongly in personal responsibility and that an individual determines his or her own success or failure, but it is important to note that there are many exceptions and that a nation as diverse as the United States has literally thousands of distinct cultural traditions. One will find Mississippi in the South to be very different culturally from Massachusetts in the North.
Climate
The overall climate is temperate, with notable exceptions. Alaska has Arctic tundra, while Hawaii and South Florida are tropical. The Great Plains are dry, flat and grassy, turning into arid desert in the far West and Mediterranean along the California coast.
In the winter, the northern and mid-western major cities can see as much as 2 feet 61 cm of snowfall in one day, with cold temperatures. Summers are humid, but mild. Temperatures over 100°F 38°C sometimes invade the Midwest and Great Plains. Some areas in the northern plains can experience cold temperatures of -30°F -34°C during the winter. Temperatures below 0°F -18°C sometimes reach as far south as Oklahoma.
The climate of the South also varies. In the summer, it is hot and humid, but from October through April the weather can range from 60°F 15°C to short cold spells of 20°F -7°C or so.
The Great Plains and Midwestern states also experience tornadoes from the late spring to early fall, earlier in the south and later in the north. States along the Atlantic coast and the Gulf of Mexico, may experience hurricanes between June and November. These intense and dangerous storms frequently miss the U.S. mainland, but evacuations are often ordered and should be heeded.
The Rockies are cold and snowy. Some parts of the Rockies see over 500 inches 1,200 cm of snow in a season. Even during the summer, temperatures are cool in the mountains, and snow can fall nearly year-round. It is dangerous to go up in the mountains unprepared in the winter and the roads through them can get very icy.
The deserts of the Southwest are hot and dry during the summer, with temperatures often exceeding 100°F 38°C. Thunderstorms can be expected in the southwest frequently from July through September. Winters are mild, and snow is unusual. Average annual precipitation is low, usually less than 10 inches 25 cm.
Cool and damp weather is common in the coastal northwest Oregon and Washington west of the Cascade Range, and the northern part of California west of the Coast Ranges/Cascades. Rain is most frequent in winter, snow is rare, especially along the coast, and extreme temperatures are uncommon. Rain falls almost exclusively from late fall through early spring along the coast. East of the Cascades, the northwest is considerably drier. Much of the inland northwest is either semi-arid or desert, though altitude and weather patterns may result in wetter climates in some areas.
Northeastern and cities of the Upper South are known for summers with temperatures reaching into the 90's 32°C or more, with extremely high humidity, usually over 80%. This can be a drastic change from the Southwest. High humidity means that the temperature can feel hotter than actual readings. The Northeast also experiences snow, and at least once every few years there will be a dumping of the white stuff in enormous quantities.
Geography
The contiguous United States or "Lower 48" the 48 states other than Alaska and Hawaii are bounded by the Atlantic Ocean to the east and the Pacific Ocean to the west, with much of the population living on these two coasts. Its only land borders are shared with Canada to the north, and Mexico to the south. The U.S. also shares maritime borders with Russia, Cuba, and the Bahamas.
The country has three major mountain ranges. The Appalachians extend from Canada to the state of Alabama, a few hundred miles west of the Atlantic Ocean. They are the oldest of the three mountain ranges and offer spectacular sightseeing and excellent camping spots. The Rockies are, on average, the highest in North America, extending from Alaska to New Mexico, with many areas protected as national parks. They offer hiking, camping, skiing, and sightseeing opportunities. The combined Sierra Nevada and Cascade ranges are the youngest. The Sierras extend across the "backbone" of California, with sites such as Lake Tahoe and Yosemite National Park, then give way to the even younger volcanic Cascade range, with some of the highest points in the country.
The Great Lakes define much of the border between the eastern United States and Canada. More inland seas than lakes, they were formed by the pressure of glaciers retreating north at the end of the last Ice Age. The five lakes span hundreds of miles, bordering the states of Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, Pennsylvania and New York, and their shores vary from pristine wilderness areas to industrial "rust belt" cities. They are the second-largest bodies of freshwater in the world, after the polar ice caps.
Politics
The United States is a republic of 50 states as well as the District of Columbia, with each of the states retaining considerable autonomy within the federation. Each of the states has its own state government, with laws differing slightly between state.
The Federal Government consists of the President and his administration acting as the executive body, the United States Congress acting as the legislative body, and the federal courts, which decide disputes. The President is elected indirectly by the people via an electoral college, and serves as both the Head of Government and Head of State.
The Congress is bicameral, comprising an upper house, known as the Senate, and a lower house, known as the House of Representatives. Both houses are directly elected by the people. While more seats are given to more populated states in the House of Representatives eg. 53 for California, but only 1 for Alaska, the Senate is equally represented by each state, which each state getting 2 seats regardless of population. For presidential elections, the number of electoral votes assigned to each state is equal to the total number of representatives and senators from the state. The District of Columbia has no representation in either house of Congress, though it is given 3 electoral votes in Presidential elections.
The Judicial Branch consists of courts, the judges of which are appointed by the President and confirmed by the Senate. The Supreme Court, consisting of nine Justices, has the final say in interpretations of the laws and Constitution of the United States.