You can find the flags under other in the decorative category of the construction menu. They will cost you $500 per flag. A list of all the flags in the pack:
USA Flag Pack:
US Flag
Rebel Flag
Gadsden Flag
US & Rebel Flags
US & Gadsden Flags
Iowa Flag Pack:
Iowa & Rebel Flags
Iowa & Gadsden Flags
US & Iowa Flags
US & Iowa & Gadsden Flags
US & Iowa & Rebel Flags
