Question: In what county in New Hampshire had significant development in the second half of the 19th century and first decades of the 20th?
Sentence (from "Franklin Falls Historic District"): The Franklin Falls Historic District is a 75 acre historic district encompassing most of the civic and industrial heart of Franklin, New Hampshire, which saw its most significant development in the second half of the 19th century and the first decades of the 20th.
Relevant evidence: Yes