A pivotal 19th-century steel-making innovation significantly reduced the cost of steel production, making it more affordable and widely available. This technological advancement involved injecting air into molten pig iron to oxidize impurities, resulting in higher quality steel. Its definition within the context of Advanced Placement United States History (APUSH) concerns its profound impact on industrialization, urbanization, and economic growth in the latter half of the 19th century.
The widespread adoption of this efficient steel production method fueled the construction of railroads, bridges, and skyscrapers. This infrastructure development stimulated economic expansion by facilitating transportation and commerce. The increased availability of affordable steel also propelled the growth of industries such as manufacturing and construction, creating new jobs and contributing to the rise of large industrial cities. Its influence on the American economy and landscape was transformative.