MARVELS IN MANUFACTURING
•	America’s factories spread slowly until about 1807, when there began the fateful sequence of the embargo, nonintercourse, and the War of 1812. 
•	Necessity dictated the manufacture of substitutes for normal imports, while the stoppage of European commerce was temporarily ruinous to Yankee shipping.
o	“Buy American” and “Wear American” became popular slogans.
•	The manufacturing boomlet broke abruptly with the peace of Ghent in 1815.
o	British manufacturers uploaded their dammed-up surpluses at ruinously low prices.
•	In one Rhode Island district, all 150 mills were forced to close their doors, except the original Slater plant.
o	Congress provided some relief when it passed the protective tariff of 1816
•	As the factory system flourished, it embraced numerous other industries in addition to textiles. Prominent among them was the manufacturing of firearms, and here the wizardly Eli Whitney again appeared  with an extraordinary contribution.
o	In 1798, Whitney seized the idea of interchangeable firing mechanisms for firearms. This principle of interchangeable parts was adopted by 1850 and became the basis of modern mass-production and assembly-line methods.
•	Whitney gave the slavery a renewed lease by perfecting the cotton gin, and by popularizing the principle of interchangeable parts, caused factories to flourish in the North, contributing heavily to the winning of the war by the union.
•	The sewing machine, invented by Elias Howe in 1846 and perfected by Isaac Singer, gave another strong boost to northern industrialization. The sewing machine became the foundation of the ready-made clothing industry which took root about the time of the Civil War.
•	For the decade ending in 1800 only 306 patents were registered, but in the decade ending in 1860 saw the amazing total of 28,000.
•	Laws of “free incorporation” first passed in New York in 1848 meant that businessmen could create corporations without applying for individual charters.
•	Samuel F. B. Morse’s telegraph was among the inventions that tightened the sinews of an increased complex business world.