The building at 402 Main, served as the Argenta post office until closing Friday.
City officials had their eye on the building for six years as the new home for the Argenta library branch, but they've had many obstacles along the way.
Obstacles including voters defeating a sales tax increase last year to pay for the move and renovation.
"For us, if we would have got it, it would have been wonderful," said the Laman Library Executive Director Jeffrey Baskin. "Would have made the process much easier, but it didn't stop our process. There's too many people in North Little Rock that want us to buy the building and so we've had some very good people step forward and say we'll get this done."
The post office has not listed a price for the purchase of the building.
Library officials estimate renovations will cost $1.8 million which they said they'll pay with bonds and loans.