Commas

Put a comma before the and in a series of items.

  “Buy bacon, eggs, and milk at the store.”

Separate the independent clauses of a compound sentence connected by a conjunction.

  “He didn’t know how she found it, but he didn’t object.”
“There is plenty of time to shop, and I plan to buy tons of food.”

If the clauses are very short, however, the comma may be omitted.

  “She understood the situation and she was furious.”

Use commas with Jr., but not with Roman numeral designations (except as otherwise specified, as in the case of emeritus trustee Andrew B. Craig, III and Henry L. “Roddy” Roediger, III in the Department of Psychology).

  “A. Leon Higginbotham, Jr., is attending Founders Day.”
“Harry Greensfelder III is not coming.”

Use commas between city and state and between date and year; also use commas after the state and after the year.

  “Atlanta, Georgia, hosted the 1996 Summer Olympic Games.”
“January 1, 2001, marks the beginning of the new millennium.”