How public policy is formed in the American system of government

Lesson 7 presented several national policy matters that have developed over the past 10 to 20 years. Please explain how public policy is formed in the American system of government. How is the problem identified? Who is responsible for determining solutions or setting the public policy agenda? (Hint: Read the examples and ask yourself these questions as you read the information presented about each.).

url for lesson 7 reading:  http://www.ushistory.org/gov/11.asp

Provide a fully developed essay of at least 500 words, and cite sources used.