Who is Stanton referring to when she writes about “one portion of the family of man”?
.

Elizabeth Cady Stanton is referring to women. Women in the context of wanting to be allowed to take on new roles in the family and society. Roles that she feels they are entitled to take in the pursuit of happiness.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.