Why was the fort laramie treaty, signed in 1851, significant to westward expansion?

The Fort Laramie Treat of 1851 guaranteed safe passage through Native American territories on the Oregon Trail and permitted the US government to build forts and roads on Native American land. It also resolved territorial disputes among the eight tribes who were signatories to the treaty, lessening the chance of emigrants encountering warring parties on the trail. A student can find this information on Wikipedia by using search terms such as 'Fort Laramie 1851'. When learning from online sites it is a good idea to verify information on more than one site.