Although he was poor, he never borrowed money from anyone.
Literal
Poor [although-かったけれども] he [topic-は] people [from-から] money [object-を] did-not-borrow.
かったけれども chains the past tense of 貧しい with the concessive conjunction. The emphasis is on integrity — despite poverty, he maintained independence by not borrowing. から marks the source of the potential borrowing.