I'm curious as to whether or not a verizon 9100em router has the ability to track history of visited websites on the network? A simple yes or no will be concise, but feel free to elaborate on any details you might feel necessary ^_^ \\
I have a feeling that the Parental Controls feature on the router may have somewhat of an ability to monitor Website activity on the network, however if it does exist it would be pretty basic, and with a speed reduction on your service.
If anything, what you can do is set up your network to use OpenDNS. If you have an account with them (free or paid, depending on what you want to use) you can apply website filtering at the DNS level and you can also take a look at every domain name that has been looked up from your connection. It doesn't show what machines visit it exactly since the service has no way of identifying that, but it will report them. See:
medium answer, follow smith's advice above if you would like to be able to do that moving forward.
longer answer is that verizon offers desktop software that is free that you load on each pc and it monitors all activities, like web, chat email etc... you can download it at www.verizon.com/freetools it is called mcafee family protection software.