Possible Clues:

• Massachusetts city with Halloween tourism
• Trading opportunity attracting a thousand in American city
• Westernmost state capital in the contiguous United States
• Deal twinned with medium US city
• Capital of 2-Down
• State capital that was a boyhood home of Herbert Hoover
• US city where infamous witch trials took place
• Witchy town
• State capital on the Willamette River
• Town that inspired 'The House of the Seven Gables'