The inca travel long distances and communicate with their neighbors

Rope bridges is the answer.

Explanation:

Inca Empire, also known as the Incan Empire and the Inka Empire was the largest empire in the pre-Columbian America. Cusco was the most important city since it was the administrative, political, and military center.

Inca rope bridges are suspension bridges over canyons and rivers built by the Inca Empire. They were part of the Inca road system and it's a proof of Inca innovation and engineering and they were very helpful since Inca people didn't use wheeled transport.

they had many gains 1 one freedom for slaves the major cause of the civil war is that the   north wanted freedom for slaves but the south didn; t creaitng the civil war

another gain they have is poltiical influence

poltiical influence is a big thing everywhere even now peoplle are always trying to get the head up in poltics thats what they did by giving the republicians a good name for freeing slaves