It is important to bear in mind that the United States of America is highly diverse. It is difficult to identify a single American attitude, or American style for the simple reason that the country is so complex.
The United States was founded in the late 18th century and as such, a great deal of American culture is couched in the ideals of the Enlightenment. Examples of this influence are reflected in the following: the Declaration of Independence's mission statement, which secures life, liberty and the pursuit of happiness; the French Revolution's ideals of liberty, equality and fraternity; and the national motto, E pluribus unum ("From many, one").
Another primary influence on American culture is the ongoing influx of new immigrants, many of whom have fled persecution or oppression in their home countries, and are seeking freedom (including religious freedom) and economic opportunity. This leads to the rejection of totalitarian practices, another widespread American attitude. By and large, Americans value the ideals of individual liberty, individualism, self-sufficiency, altruism, equality of opportunity, Judeo-Christian morals, free markets, a republican form of government, democracy, populism, pluralism, feminism, and patriotism.