After lots of googling for information, I now can console into all my Cisco devices (one right after the other) with my serial-usb connector and Mac terminal. I just had to enable root user on my Mac. That is a bit scary, but I know to be careful with that, and I know to Ctrl-A & Ctrl-\ to close out of my Cisco screens.
It is amazing what leaving the work scene and coming back does for getting through being ‘stuck.’
Here’s to: Moving on to more challenges!