CenturyLink— Formerly CenturyTel and Qwest, formerly US West.

Also, completely unrelated, but they are the namesake of the CenturyLink football stadium, home of the Seattle Seahawks. This is how I learned of their existence, which proves that there is at least some nominal value to having a stadium named after your company.

http://en.wikipedia.org/wiki/CenturyLink_Field

Also merged with Embarq, which was previously Sprint's local arm.

And US West spawned out of Ma' Bell.

Same here, until they acquired Appfog (phpfog) last year.

They've been a provider for other providers so their presence has been masked a bit. Many smaller, regional, ISPs frequently resell through them.

They suddenly got a lot bigger when they bought/merged with Qwest a few years back. They weren't one of the baby bells -- they grew independently.