Ulysses Grant was a good general but his presidency was marred by corruption of his appointees. Both parties had legislators who accepted bribes of money and stocks from railroads and robber barons. The Republican party switched its allegiance to moneyed interests since then and democrats have followed their example. Labor was exploited by people like Carnegie and his henchmen and farmers were exploited by the railroads charging exorbitant freight. The rich resources of the land taken from the natives and the forced labor of the poor blacks and whites (Irish, Italians and Polish) led to the gilded age of the gay (happy) nineties. The inventive genius of the immigrant Americans led to prosperity of relatively few Americans but the nation began overtaking Great Britain as the largest economy in the world. Alfred Mahan, a smart naval officer with a sound knowledge of military and naval history put forth a plan to make America a great naval power. Britain forged an empire due to its naval supremacy as had the Dutch, Spanish and Portuguese before. Indian ships going to the Gulf for trade and Haj had to pay a tribute to the Portuguese during the Moghul rule. British and American pirates had looted Spanish ships in earlier centuries and the sinking of the Spanish Armada brought victory to Elizabeth the first over Spain's Philip.
Theodore Roosevelt, a racist man itching to go to war was the vice president of Mckinley. An American ship blew up in the harbor at Havana, most likely by accident. William Randolph Hearst owning a chain of newspapers accused the Spanish of sabotage and orchestrated the Spanish American War that brought us the territories of Cuba, Puerto Rico and Philippines. Remember the Judith Miller story and the belated apologies by the New York Times and Washington Post about not investigating the WMD lies that led to the current war in Iraq. Mckinley was just as devout and ignorant as our current president. He stated that he had spent the night in prayer and god had granted him the mission to Christianize the Philippinos. A knowledgeable subordinate informed him that the bulk of the Philippinos had been Catholics for over two centuries. The genocidal attack on the Philippino freedom fighters caused nearly hundred thousand deaths of men, women and children and planted the seeds of the Muslim Moro insurgency which still plagues the Southern Philippines.
Mckinley was assassinated by a loony anarchist and Teddy became the president. He forcibly carved out the new country of Panama from Colombia so he could build the Canal. America was the number one power by this time and repeated military excursions to change legitimate regimes all over Central and South America and the Caribbean began. Woodrow Wilson, a later president who was an even worse racist, began his term by firing most black persons at high levels in the Federal Bureaucracy. He invaded Mexico and Haiti on the pretext of spreading better government and later sent American troops to Russia to topple the Bolshevik government after the Russian Revolution. His crowning follies and crimes were much worse. American banks had been loaning money to both Britain and Germany during WW1. The British debt was ten times greater and two billion dollars (current value 40 billion) and the bankers who had financed the loans pressured Wilson. They needed Britain to win so the debt could be collected. Wilson had campaigned on keeping America out of the war but pressured by his rich cronies, he led America to war to aid the British at the cost of 500,000 American casualties and billions of dollars to save the wealth of his rich supporters. This seems to be the modus operandi of other presidents to follow.
His second crowning folly was his egotistic grandeur during the post WW1 peace negotiations in Paris, where he strutted with his Fourteen Points and his insulting neglect of the US senate that sank The League of Nations due to non-ratification by the senate. Those toasting the Indo-US nuclear treaty need to learn that there could be many a slip betwixt the cup and the lip. He claimed that WW1 was the war to end all wars to make the world safe for democracy. Of course that did not include liberating the colonized Indians, Vietnamese, Cambodians, Laotians, Kurds and most Africans. He allowed the vengeful Clemenceau of France to impose a crushing burden of reparations on defeated Germany that led to the hyperinflation of the Weimar Republic, resultant ascendancy of Hitler and the even more devastating WW2 that the farsighted John Maynard Keynes warned against.