Respuesta :

1840s
Factory-made agricultural machinery increases farmers' need for cash and encourages commercial farming

1841
Practical grain drill patented

1842
First grain elevator, Buffalo, NY

1843
Sir John Lawes founded the commercial fertilizer industry by developing a process for making superphosphate

1844
Practical mowing machine patented

1847
Irrigation begun in Utah

1849
Mixed chemical fertilizers sold commercially