Economic growth occurs in cycles, which combine to create peaks and valleys of opportunity
Just as energy waves in the ocean combine to create waves of different heights, the short-term and medium-term cycles combine to create long-term economic cycles, which define the fate of nations.
Economic growth is made up of many cycles that operate at different lengths of time, and they add up to peaks of different size in the same way that energy waves in the ocean combine to produce waves of different sizes. For instance, the economy undergoes the short term cycle of the individual year -- every economy sees a recession every January, though typically we look at "seasonally adjusted figures" to better understand the true underlying reality. Then there is the business cycle, measured from the start of a recession to the start of the next recession, a cycle which in the USA has averaged 7 years, but sometimes is as short as 18 months and other times has gone almost 11 years. Then typically there are multiple business cycles that share a common theme, such as the post war boom 1945-1973, which was 5 business cycles strung together (counting the double dip recession of 1958 and 1960 as a single recession). Or, going back further in time, there was the boom in commodity prices from 1848 to 1873, which gave the USA a long period of prosperity in the middle of the 1800s. Then there was the era of weaker growth from 1873 to 1893, what in Britain they referred to as the Great Depression, until the 1930s stole that name.
This long era of prosperity, 1848 to 1873, was made of multiple business cycles, and the subsequent 20 years of slower growth was also made up of multiple business cycles. And yet in some large-scale sense, we can see it as a single cycle, from 1848 to 1893, a period of faster growth followed by a period of slower growth. And then 1893 kicked offer another episode of faster growth, from 1893 to 1920, followed by slower growth from 1920 to 1932. And though we typically date the post war boom to 1945, we could take a step back and see the whole period from 1932 to 1973 as one of accelerating growth. After 1973 comes a long era that some economists call The Great Stagnation, a period of several decades during which technological innovation stalled, productivity growth declined, and worldwide growth slowed, though some Asian nations did extremely well during this era. There is probably some analytic usefulness to this idea that the individual business cycles combine together in ways that create cycles that operate over a larger scale.
And pulling back to an even more macro scale, some economic historians have speculated about very long term cycles, “the secular trend,” cycles that define the whole history of civilizations, booms and busts that last for centuries. Fernand Braudel has written about that topic:
https://www.amazon.com/Perspective-World-Civilization-Capitalism-15Th-18th/dp/0520081161/
One of the great questions of economic history is why some nations are above or below the trend, at any given time, and during any particular cycle. For instance, consider how prosperous the world was after World War II. The USA was also prosperous, and yet during these years the USA grew slowly when compared to many other nations. Why is that?
In 1940 and 1950 the USA was the only nation which had infrastructure and production capacity not affected by the war. It had the best roads, ports, railroads, energy plants, coal mines, oil wells, airports and scientific research laboratories. It had the best of everything. So why did it do so poorly?
During the post war boom, Germany, France, Italy, Japan and many other countries grew faster than the USA. The USSR managed to grow faster than the USA from 1929 to about 1960, and during this time the USSR surprised everyone with its technological advances. Under Stalin the USSR transformed from a mostly feudal and agricultural society to a society that was able to beat the USA at a number of technical achievements, most famously putting the first satellite in space (Sputnik) then the first dog in space, then the first man in space, and then the first woman in space (an effort that came to fruition after Stalin’s death, but helped by the vast program of industrialism that he had pursued).
The special era for the USA, when it grew faster than any other nation, lasted from 1848 to 1929. There was an epilogue around 1943-1945 when the USA economy did well relative to other nations, but those were exceptional circumstances.
It remains one of the great unanswered questions of economic history, why did the USA do relatively badly at a time when it seemed to have every advantage? This is a complex topic and there are many variables, but sometimes it is interesting to put that complexity aside and focus in on the influence of a single variable. See my essay Why Did The West Deindustrialize which explored the possibility that the USA dollar was overvalued for most of this time.