Reddit user deck up more and more to find the core reason of existence of this room. He found out that this chamber was the part of underground railroad of 19th century America. This railroad was used by African-American to free black people from slavery and move them to Canada from America. They chose this house as the underground railroad source because this house was near the border which made transferring of people easier. This organization was named as underground rail road so that no one can find out the sole purpose of this organization.