Steel barbed wire
Barbed wire fencing may not be the biggest deal in most people’s eyes, but it may have been the greatest invention of the 1800’s that changed the United States forever. Many Americans in the early 1800’s looked west to settle and make a fresh start, but had no means or purpose to do it. Raising cattle was a profitable industry, but cattle were all free grazers and wooden fences were expensive and could not keep cattle herded. Steel barbed wire was incredibly cheap to make and buy, and helped grow and expand the number of cattle one could manage, and gave settlers a reason to venture out west to the open grassland prairies. This demand helped spark the Mexican-American War, which ended up winning the United States vast areas we call home today.
Over 90% of trade occurs through traveling on water, which means ships are absolutely essential for maintaining a healthy economy. We don’t think about it as much today, but shipping not too long ago was an extremely dangerous but vital part of an economy. Many ships sank or were damaged because ropes couldn’t withstand tension, and would fray or break in critical situations. Ships had to also be kept at a certain size in order to harbor them and keep them from going adrift on a stormy day. Steel wire helped solve that problem, and served as a more practical and useful alternative to ropes in high tension situations.