Amex charges a slightly higher fee per transaction to merchants than Visa and Mastercard. So some merchants don't accept Amex for that reason. That said, Amex is accepted at most places in the US (and plenty internationally as well). Amex has always treated me well.
Amex Gold, Amex Bonvoy, Amex Hilton Honors Surpass, Amex Every Day, Amex Hilton Biz, Amex Delta Biz, Barclays Arrival+, Barclays Rewards, Capital One VentureOne, Capital One Quicksilver, Chase Freedom, Chase IHG Rewards, Chase United Explorer, Chase Sapphire
