Donald K. and Esther V.(Whistler) Gard's of Union City, Ind

I am researching my mother's and father's family from Darke County, Ohio and Randolph County Indiana. The town is Union City, Indiana and Union City, Ohio. It's on the stateline so the town has the same name but different states and different counties(and different time zones). My parents were born and grew up in this town until my dad joined the Navy, married my mom and started traveling.
My mother's family names are HUTCHINS,MARTIN, MILLER, ST.JOHN, SWORD, WHISTLER, WHISLER,YODER,
My father's family names are BROOKS,BROWN,BRUBAKER,BUTT, GARD, JENNINGS, MATHEWS (MATTHEWS), ZUMBRUM