The Mayhew Cabin in Nebraska City is reopening after seven years and on Juneteenth.The cabin served as a stop on the Lane Trail, or Free-State Trail, where 12 enslaved people who had escaped from Missouri rested on their way to freedom. It became the first site in Nebraska added to the National Park Service's Network to Freedom.Doug Kreifels recalled, "For many, many years, I've driven by and wondered: What happened there? Why isn't this open?"T…