I believe the answer would be cotton gin because the invention of the cotton gin was able to become more efficient in harvesting cotton.
Where is the blank? I’m sorry to answer without a answer just elaborate in comments
If I remember correctly it is Spain
European Emigration to the U.S. 1851 - 1860
Although the Irish potato blight receded in 1850, the effects of the famine continued to spur Irish emigration into the 20th century. Still facing poverty and disease, the Irish set out for America where they reunited with relatives who had fled at the height of the famine.
I think it was near Pennsylvania
