What do the following words, number, and phrase have in common?

1. Boot

2. Penny

3. Grape

4. Open

5. Sole

6. 500 

7. Clam chowder

 

Answers:

 

Each clue can be preceded by a US capital city to make a common phrase:

 

1. Denver boot

2. Lincoln penny

3. Concord grape

4. Augusta Open

5. Dover sole

6. Indianapolis 500

7. Boston clam chowder