When did the "modern" era begin?

[J. J.]

Intertationally, "Modern History" traditionally began in 1453, with the fall of Constantinople and the end of the Hundred Years War.  Late modern history began in either 1789 (French Revolution, Washington as President) or 1815  (end of the Congress of Vienna).

US history generally makes the break at 1877 (end of Reconstruction).  I really think another break can be made in 1945, with the end of World War II (the "Post War" years).  That might have ended with 1980 as the "Superpower Years."

Some breaks might be "The Republic of Compromise" (1776-1865),  "The Growing Union" (1865-1933), "Big Government" (1932-1989), "World Domination" (1989-present.)

"The Republic of Compromise" (1776-1865):  Slavery and sectionalism are the big issues.  Globally, Europe is the Center of power (Britain in particular).

"The Growing Union" (1865-1933):  Industrial growth and western and colonial expansion.  The US became a "great power" during this period.  Globally, Europe is the Center of power (Britain v. Germany).

"Big Government" (1932-1989):  Both military and social programs expand, numerous wars.  US becomes a superpower (at best two others).  (Western Europe recedes, USSR v. US)

"World Domination" (1989-present):  US is the supreme military power and the only power that can project military power globally.  Culturally, US culture becomming dominant.
Economically, US dominates the planet.  (North America now dominant)

[J. J.]

If you want to look just at one factor, a stable "two-party system,"  it didn't exist prior to 1865.

[J. J.]

If I were to divide US History onto four easy pieces for study, I would pick:
(1588 - 1763) The Colonial Era: From the Spanish Armada to the Treaty of Paris
(1754 -  1877) A New Nation: From the Albany Congress to the End of Reconstruction)
(1862 - 1935) The America of Business: From the Morrill Act to the Wagner Act
(1914 - present) Arsenal of Democracy: From World War I to the Present Day

These are similar to J.J.'s erae, except I included a colonial era, don't see the need to seperate the last two decades into a sperate era as of yet and I made them overlap.

One problem I have is 1989.  The world changed when the USSR was no longer a superpower.

The US became the superpower by outlasting everybody else.   That both changed our way at looking as ourselves and the world and how the world looked at us.

[J. J.]

If I were to divide US History onto four easy pieces for study, I would pick:
(1588 - 1763) The Colonial Era: From the Spanish Armada to the Treaty of Paris
(1754 -  1877) A New Nation: From the Albany Congress to the End of Reconstruction)
(1862 - 1935) The America of Business: From the Morrill Act to the Wagner Act
(1914 - present) Arsenal of Democracy: From World War I to the Present Day

These are similar to J.J.'s erae, except I included a colonial era, don't see the need to seperate the last two decades into a sperate era as of yet and I made them overlap.

One problem I have is 1989.  The world changed when the USSR was no longer a superpower.

The US became the superpower by outlasting everybody else.   That both changed our way at looking as ourselves and the world and how the world looked at us.

I disagree.  As far as the US in concerned, we merely traded Jihadists for Communists as our boogeymen of choice when the Cold War ended.  That change was not a fundamental one in how we perceive ourselves.  We are still the shining city on a hill that is best example and guardian of all that is good in Western Civilization.  Now while 1989 would certainly be a pivotal and defining event for Europe (and thus European history) it has been but of minor effect on the US  (and thus US history).  That divergence of the importance of 1989 is part the reason that Western Europe and the US have drifted apart since then.

As of 1989, basically, our whole place in the world changed.  Even today, we are not looking at the enemy in the same way that we did then.  We are certainly not looking at Europe in the same way.

Conversely, Europe is looking at us differently and the emeny is looking at us in whole different way.