If you take even a casual look at American history, you will see that major social changes commenced in about 1830–e.g., the Abolitionist movement, Nat Turner’s revolt, first-wave feminism, the 2nd Great Awakening. Why? One major factor was improved transportation. The Erie Canal opened up the Midwest and made New York the largest and richest city in America. Train travel was another factor. People moved around more, spread ideas and technologies, etc. The roads and trails for conventional travel were also improved. The Oregon Trail started taken wagon traffic in 1836.
Looking deeper, we can ask how the Erie Canal (completed in 1825) and the railroads came into being, or the preconditions for these innovations. One essential element was iron ore. The canal, the railroads, and the trains themselves were made possible by iron technology. Try digging the Erie Canal with wooden shovels or sharp rocks.
Another factor was the invention and spread of telegraphy, which used the railroad right-of-ways even though these strips of land were not cleared for this purpose. Another metal, copper, was essential to telegraphy. And, of course, large scale copper mining depended on iron and steel (an alloy of iron and carbon) tools and machinery.
Starting in about 1820, coke from coal replaced charcoal in the iron smelting process. The Erie Canal and the railroads soon brought iron ore east to New York and Pennsylvania.
These technologies were actants in an assemblage (see Latour, DeLanda, and others). And the assemblage facilitated more and faster communication. This is the connection to social systems theory. Social and psychic systems structurally couple with all kinds of technology and material artifacts. Or we might say that communication enlists psychic systems and materials technologies to promote its own autopoiesis.
The so-called Long Eighteenth Century has been dated from as early as 1660 to as late as 1832. (Dejean, J. (2012). A Long Eighteenth Century? What Eighteenth Century? PMLA,127(2), 317-320). 1688, the year of the Glorious Revolution, is the standard beginning of this era. This is basically the period when functional differentiation emerged and became irreversible.
In England, the 1832 Reform Act marked the end of the long 18th century for some scholars. Another year cited is 1815, the year of the Battle of Waterloo. But rather than focusing on landmark battles or political events, we might look more closely at social change, looking particularly at material technologies.