Edmond-Charles Genet was a French diplomat to the United States during the French Revolution. He was dispatched to the United States to try to encourage American support for the French wars against other European nations, primarily Britain. Citizen Genet ignored official diplomatic avenues, instead focusing on organizing popularly-supported mercenaries to fight Britain’s ally, Spain, in Florida. His success undermined Washington’s proclamation of neutrality, and Washington widely condemned his actions. The matter came to an end when a different form of government came to power, and Genet was branded a criminal in France.

The Intolerable Acts was the collective name for the series of restrictions placed on the New England colonies in the events preceding the American Revolution. The other answers were causes of the War of 1812.

The Battle of Gettysburg was the decisive turning point in the Civil War. Coming as the culmination of an invasion of the Northern states by the Confederate Army, the Battle of Gettysburg was an overwhelming Union victory. The Union win made the Confederate troops take a torturous retreat that weakened and morale. While the war would continue for almost two more years, the Confederacy was fighting off the back foot for the remainder of the conflict. Although Robert E. Lee resigned as commander of the Confederate Army after the battle, his resignation was refused, and he remained in the role until 1865.

The United States had always had a special interest in Spain's Caribbean colonial possessions, as they lay so close to the U.S. mainland. In 1898, the Naval battleship U.S.S. Maine was stationed in Havana harbor off the coast of Cuba when it sank under mysterious circumstances. The outcry in the press over the destruction of the American ship made the public and politicians clamor for a war to free Cuba from Spanish rule.

The Spanish-American War was fought simultaneously against Spanish possessions in the Caribbean and the Pacific.  Claiming to defend Filipino rebels, the United States invaded the Philippines and fought the Spanish there, soundly defeating them.  From 1899-1914, the US fought the very Filipino insurgents they were claiming to defend in their invasion in 1898.

First stated by President James Monroe, the Monroe Doctrine became a long-standing tenet of American foreign policy.

The Adams-Onis Treaty, signed in 1819, ceded control of Florida from Spain to the United States. In addition, it settled the boundary dispute between the furthest western settlements of the United States, in what is now Texas, with the viceroyalty of New Spain, (now Mexico). The Treaty is generally considered to be the close of the first wave of American expansion; it was not universally respected, however, and many western Americans refused to recognize its legitimacy—continuing to settle in the territory west of the boundaries drawn up: in modern-day New Mexico and Colorado. 

In 1819, the United States bought Florida from Spain in the Adams-Onis Treaty.

The Rush-Bagot Treaty was a demilitarization treaty signed between Great Britain and the United States following the end of the War of 1812. It forbade the maintenance of more than a few naval ships on the Great Lakes territory between the United States and British North America. As importantly, it laid the foundation for a future agreement to be reached with Canada that has ensured that the northern border of the United States has remained demilitarized for two centuries.

Robert E, Lee was uneasy about secession throughout the crisis that developed following Abraham Lincoln's election, and was not sure about joining the Confederacy.  Lee was offered command of the United States Army before his home state of Virginia seceded, which caused him to join the Confederacy.  All of the other answer choices were Union generals who would come to prominence later in the war.