Better sentence-writing in 30 minutes a day - Dianna Campbell 1995

Commas to set off city from state
Cumulative review of commas
Punctuating sentence combinations

This unit simply allows you to practice all the different comma rules you’ve learned in this chapter. But before beginning the exercise, please study these two additional rules.

Commas to set off city from state

You normally use one comma between the name of a city and a state and another comma after the state. For example:

1. (a) The authors of The Best insist that New York, New York, is home to the best hamburgers in America.

2. (a) New Haven, Connecticut, is the city where they found the best pizza.

The only exception is when the city and state come right before another punctuation mark, such as a period or a semicolon. In these examples, you use only the comma between city and state:

1. (b) The authors of The Best insist that the best hamburgers in America are served at the Campus Dining Room Restaurant and Bar in New York, New York.

2. (b) Peter Passell and Leonard Ross really liked the pizza at The Spot in New Haven, Connecticut; in fact, they called it the best pizza in the United States.