I can't really categorize them so I'll just list out all these great last names for your OC's. this is kinda short so I might make a part two but this should suffice for now(:
- Adams
- Allen
- Anderson
- Baker
- Beckett
- Brady
- Brown
- Campbell
- Carson
- Carter
- Cassidy
- Clark
- Connors
- Cook
- Cooper
- Dawson
- Davis
- Davies
- Edwards
- Evans
- Fisher
- Fitzgerald
- Grady
- Grayson
- Green
- Hall
- Harris
- Harrison
- Hill
- Iben
- Iden
- Islands
- Jackson
- James
- Jefferson
- Jones
- John
- Johnson
- Kennedy
- King
- Kramer
- Lee
- Lewis
- Lincoln
- Martin
- McKenzie
- Miller
- Moore
- Murphy
- Nabers
- Nadler
- Nahl
- Oachs
- Oak
- Oballe
- Obin
- Parker
- Presley
- Quinn
- Reed
- Roberts
- Robinson
- Sawyer
- Scott
- Slater
- Smith
- Taylor
- Tucker
- Turner
- Underwood
- Uttley
- Utton
- Vallee
- Vallerand
- Vanderbuilt
- Voyer
- Walker
- Wright
- White
- Williams
- Wilson
- Winston
- Wood
- Xenos
- Xenakis
- Young
- Zadina
- Zecca
- Ziembacomment if these helped!
-holly