Question: what are the largest marathons in the us?
Answer: Chevron Houston Marathon. Carlos Alvarez / E+ / Getty Images. ...  Los Angeles Marathon. Harry How / Getty Images Sport. ...  Boston Marathon. Getty Images. ...  Medtronic Twin Cities Marathon. WireImage / Getty Images. ...  Portland Marathon. ...  Bank of America Chicago Marathon. ...  Detroit Free Press/Talmer Bank Marathon. ...  Marine Corps Marathon.