en.wikipedia.org/wiki/Telephone_numbers_in_the_Americas

All countries in the Americas use codes that start with "5" except for: Canada, the United States and some Caribbean countries under the North American ...

countrycode.org/usa

EASY TO REMEMBER URL: 'CountryCode.org/usa' for United States country code 1 country codes US and United States phone number.

ccm.net/faq/48001-how-to-call-the-united-states

If you are located within the United States and are ... by the applicable country code and 7 or 8-digit phone number.

www.howtocallabroad.com/usa

Complete resource on how to call the United States of America: country code, area codes and more international calling info.

www.tripadvisor.com/Travel-g191-s605/United-States:Telephones.html

Inside United States: Telephones - Before you visit United States, visit ... If you make a call from a phone with an area code which is different from the area code  ...

www.csgnetwork.com/usphoneareacodesbyac.html

Provided for your use by CSGNetwork.Com and Computer Support Group.

fakenumber.org

Were you to make up a random US phone number yourself, there is a high chance of your number ending up being valid. However, with Fake Number's free and ...

support.twilio.com/hc/en-us/articles/223183008-Formatting-International-Phone-Numbers

This is an internationally-recognized standard phone number format that will help ... For example, here's a US-based number in standard local formatting: (415) ...

www.united.com/web/en-US/content/help/phoneorder.aspx

To complete the reservation or to provide your payment information over the phone, you may contact United Reservations in the U.S. and Canada at ...