Possible Clues:

• Old Glory's land, for short
• Stars-and-stripes land, informally
• Uncle Sam's land, proudly
• The States, for short
• Lady Liberty's land, familiarly
• 'Merica
• Good ol' country, for short
• Its b'day is July 4th
• Where D.C. is, familiarly
• It's a good ol' country