Britannica Educational Publishing 
Executive Branch of the Federal Government [PDF ebook] 

The founders of the Constitution created the office of the President to be the Chief Executive of the United States, as well as an important figure the nation could turn to. This book covers the role and duties of the executive in the office of President, describing how those duties have changed and evolved throughout the history of the United States. There is also plenty of helpful information detailing the complicated election process, from the caucus to the Electoral College, helping to educate a new generation of voters about their impact on electing the next executive officer.