Which preposition to use with southlands

during Occurrences 1%

The paper money used for change was called "shin plasters" and much of it flooded the southland during Civil War days.

in Occurrences 1%

"And I accept this noble chieftain equally as the representative of this Southland in the spirit of his retirement from struggle.

with Occurrences 1%

The Russian Chamberlain Rezánov, in charge of the Czar's northwestern possessions, had found a starving colony at Sitka and had brought a cargo of goods to the more productive southland with the hope of exchanging it for foodstuffs.

Which preposition to use with  southlands