Final answer:
Americans' decline of trust in their government has increased due to historical events such as political scandals, economic changes like the Great Depression and the Great Recession, as well as partisan polarization. These events have profoundly influenced citizens' perceptions of government efficiency, integrity, and their role in society.
Step-by-step explanation:
To explain why Americans' decline of trust in their government has increased over the span of the twentieth century, one must consider historical, political, and social contexts. Key events such as political scandals, the Great Depression, and shifts in voting patterns have led to changing perceptions of the government. The Founders' awareness of corruption and their warnings against centralized power resonate throughout American history, highlighting a traditionally cautious attitude towards government.
Over the course of the twentieth century, key events have challenged Americans' faith in their leaders and the political system, notably during the late 1960s and 1970s. The Great Depression catalyzed a shift in national identity and citizens' expectations of their government, a change that is evident even in contemporary politics. Moreover, political scandals, particularly in the late 1880s, the economy's shift from manufacturing, the implementation of Reaganomics, and the outcomes of the Great Recession have all contributed to widening inequalities and have led to a tangible sense of economic disenfranchisement among many Americans.
In response to social issues, citizens initiated changes and began to investigate societal problems more deeply. An increase in the level of trust in government was briefly noted following the 9/11 attacks, but this did not reverse the long-term trend of declining trust. The partisan polarization that has characterized recent decades also reflects citizens' growing skepticism towards government and a shift towards more conservative views post-9/11, although it remains to be seen if these changes are permanent.