COTTLEVILLE, Mo. (AP) — A creek in an eastern Missouri county has been renamed to commemorate a slave who risked his life to provide information to the Union army during the Civil War.

Tributary B in St. Charles County was renamed last month to honor Archer Alexander for his heroism, KSDK-TV reported . County officials, along with the O'Fallon City Council and Cottleville Board of Aldermen, all passed resolutions to change the creek's name to Archer Alexander Creek.

The Missouri and U.S. boards on Geographic Names gave final approval of the decision.

Alexander came to St. Charles County as a slave in 1830, according to Steve Ehlmann, a county executive and author of 2004 book "Crossroads: A History of St. Charles County, Missouri."

"His owner was a Confederate sympathizer. He (Alexander) overheard him and some of the other neighbors talking about sabotaging the bridge over the North Missouri Railroad," Ehlmann said. "He also found out that on the Campbell farm that there were guns that were being hidden. You couldn't have a gun unless you were in the militia during the Civil War here."

Ehlmann said Alexander's bold decision to share information with the Union army likely saved dozens of lives.

"It took a lot of courage," said Ehlmann. "It meant he eventually had to leave his wife and run away."

Alexander escaped to St. Louis, where he met abolitionist William Eliot, he said. Eliot founded Washington University.

Ehlmann found in an 1875 atlas that "Tributary B runs through what was the Campbell farm where Archer Alexander found the guns that he reported that was the reason he had to run away."

He said, "It's important that we understand during the Civil War, it wasn't just whites who were working to save the Union


Information from: KSDK-TV,