The Han Dynasty is one of the most glorious periods in Chinese history. The Chinese today—they call themselves Han Chinese—refer back to this Dynasty, a Golden Age in cultural production [and] economic prosperity.
It was a period when China itself really created the bureaucratic system that was going to last down to the early part of the 20th century—based on a civil service system—and that grew out of Confucian teachings in the 6th century and following centuries of the late Bronze Age. So, it was a consolidation of Confucian thought that sets this government on a kind of bureaucratic course that remains the standard hallmark of Chinese administration for several ensuing centuries.
The period is traditionally divided into a Western Han period—when the capital was at Chang'An, largest city in the world, wealthiest city on Earth, at that time—and an Eastern Han period, which runs for approximately 200 years as well, when the capital was relocated to Lo Yang.
This is a period of great expansion and trade. They had heard of the Roman Empire and they knew of its might and its wealth and its prosperity, and they wanted to trade their silk with that empire, and ultimately they do link up with various middle men in the Central Asian states—with the Roman Empire itself—and the Silk Trade begins in earnest during this era, 2nd century BC. That goes on to become the world's largest land trade corridor. It remained that until the 17th century, when ocean trade took over again.
One of the great trade items—besides silver—that the Chinese were trading their silk and some of their ceramics for during the early Han was the horse. A new kind, or a new breed, of horse was now introduced into China. It became extraordinarily popular. It was bigger, faster, stronger than the smaller horses, the kind of steppe ponies that they been using to pull carriages and war chariots previously. This horse was one that could be mounted and used as a warhorse in combat. It could also be tethered, of course, to carriages and war chariots as well, as they had in the past. But it becomes almost a symbol of early Han and it was one of the main items that silk was traded for.
So, it was a period, just preceding Han, of great unification of the written language, weights and measures, and transportation which made trade, of course, possible to flourish. And it certainly does that during the Han.