You will need to become familiar with the following topics:
Roanoke Colony
Jamestown
Thirteen Colonies

The Thirteen Colonies
(Click on the image to view a bigger picture.)
French and Indian War
Intolerable Acts
The Boston Massacre
The Boston Tea Party
Committees of correspondence
The First Continental Congress
Articles of Association
The Second Continental Congress
The Declaration of Independence
The Articles of Confederation
The War of Independence
George Washington
France in the American Revolutionary War
Marquis de La Fayette
Battle of Yorktown
The Treaty of Paris
The Constitutional Convention
The United States Constitution
The United States Bill of Rights
The Louisiana Purchase
The War of 1812
The Monroe Doctrine
The Oregon Trail
The Indian Removal Act
Trail of Tears
The Mexican-American War
The Texas Revolution

The territorial growth of the USA
(Click on the image to view a bigger picture.)
The California Gold Rush
The Homestead Act
The First Transcontinental Railroad
The Missouri Compromise

The division into north and south
(Click on the image to view a bigger picture.)
Bleeding Kansas
King Cotton
The cotton gin
The Fugitive Slave Law
The Confederate States of America
Abraham Lincoln
The origins of the American Civil War
The Battle of Fort Sumter
The American Civil War
Ulysses S. Grant
Robert E. Lee
The Emancipation Proclamation
The Battle of Gettysburg
The Gettysburg Address
The Union blockade
Sherman's March to the Sea
The Black Codes
The Reconstruction Act
Segregation (Jim Crow Laws)
Immigration to the United States
Theodore Roosevelt
Woodrow Wilson
The Roaring Twenties
The Great Depression
Hooverville
The New Deal
Franklin Delano Roosevelt
Extra information:
(The complete list of Presidents of the United States)