The country was founded via american revolution in 1776. America has a rough start with the articles of confederation but the government became more unified with the constitution. There's the american civil war followed by the Spanish-american war.
Woodrow Wilson was president when the WW1 of OTL was going on. He tried to stay out of it until the Zimmerman telegram was intercepted by the British leading to a direct confrontation with Germany. Without a world war to push america into Europe, the country remains non-interferrant in the affairs of Europe.
The panic of 1929 hit america hard compared to other countries but not as badly as the OTL great depression did. Frankland Roosevelt does not run more than 2 terms because it was the great depression and WW2 in OTL which increased his popularity.
In December 1941, Japan still launches an attack on Pearl Harbor and the resulting pacific war happens. The war ends around the same time because the US has all of its forces in the pacific but it doesn't have the atomic bomb. After the war, the US found 2 I-400 class Japanese submarines. These could submerge whilst carrying 3 planes. In OTL, they were destroyed during the dawn of the cold war in 1949 to prevent it from falling into soviet hands. Without the soviet union, the US reverse engineers the sub and possible incorporate its design into today's ships. In OTL, the US rebuilds Japan making it an economic powerhouse and more peaceful. This was partially because Japan actually surrendered due to the atomic bombs and the fact that the US was now on the world stage and entering a standoff with the soviet union. In this timeline, the US forces Japan to pay massive reparations and the country was put under American occupation until 1950 when the Hiroshima Republic was established. During the days of the Hiroshima republic, the country tried producing more money to pay off their debt to america but suffered severe inflation. Eventually, there was a Japanese man elected who transformed Japan into a fascist state once again. Anti american sentiment ran hot in this new japan and the Chinese were viewed as subhuman. The country began the second pacific war in 1972 when it invaded China and waged war on the US with a risky yet brilliant plan in 1975. The plan backfired and the bombings of Hiroshima and Nagasaki followed. In the aftermath, japan became more peaceful.
In the early 1960s, the civil rights movement inspires a similar movement in the Austrian-Hungarian Empire. America achieves its first nuclear test in 1965, the same year in which the big 4 signed the non proliferation treaty. It faced some scrutiny from Germany but the UK cared very little as they figured that the US would never use them as they never went on the worldwide political scale. In the 80s, america built its first space station and later docked it with the modular Friedan space station.
The US is facing another election in November 2016. Hillary Clinton is about to finish her second term. Donald trump doesn't see any need to run as the United States is not dealing with terrorism nor is it entangled in foreign affairs. Instead, it seems like Ted Cruz is going to win nomination, though it doesn't look like Jed Bush is going to drop out. On the democratic side, you have Barack Obama followed by Bernie Sanders.
The September 11 attacks did not occur as there were no mujaheddin to start the rise of jihad. In OTL, the trump international hotel and tower is the 2nd tallest building in Chicago IL; it was originally slated to be taller than the Willis tower but was shortened in height due to 9/11. In this timeline, the building is taller than the wilis tower and is the tallest in america.