From the Television Obscurities YouTube channel, here’s an unusual ABC network ID from the 1950s. What’s unusual about this particular network ID is that it mentions stations throughout North America, not just the United States.
Exploring forgotten TV from the 1920s to today.
As far as I know, ABC never had Canadian stations, even though the signal from many of their stations reached Canada so the channels were available in Canada. So they technically were broadcasting to more than just the US. I can’t say if they owned any Mexican stations.