During the mid-1800s which region relief most on factories and a workforce of immigrants

The northern region

The area had numerous  textile  and cotton processing industries which were the epitome of British achievement. The region saw a soaring of immigrants, who provided labour. this was in sharp contrast with the south which relied on plantation agriculture with slave labour being predominant.

Explanation:

"the sepoy rebellion was the result of many, many influences and stressors on the cultures of india living under british rule. in britain, it's called the sepoy mutiny on the indian mutiny, but in india, it's called the first war of independence.

the main reason is concerned to the british paramountcy , the belief in british   dominance in india political, economic and cultural life had been introduced in india about 1820."

"they were forced to grow crops that benefited the colonizing nations instead of feeding their own people."

the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation.