The coolest part of that trip was when Mitt Romney sat at our booth and chatted with us during a campaign stop to a local diner.
Today, planning for a trip like that would be much easier. To track upcoming candidate appearances in Iowa, the Des Moines Register has an Iowa Caucuses Candidate Tracker, where you can sort appearances by party, candidate, date, or city. That site also aggregates the total number of event appearances each candidate has made in Iowa.
You can find the same information for New Hampshire here on the New England Cable News site. Democracy In Action's P2016 Race for the White House pages have reports for South Carolina and other states. This link from the New York Times shows the dates for the upcoming caucuses and primaries.
Watching presidential campaign developments will certainly be a sustained focus when we return from winter break, and so it would be fun to share these sites with our students. As a recurring activity, we could have them record candidate appearances on a map that they would annotate with news coverage about that event.
The best online tool to record that same data would be to create a StoryMap. StoryMapJS lets map tell stories. It is unbelievably easy to use and makes amazingly beautiful interactive maps. Here's a tutorial on using StoryMapJS. (I assigned my US History students to make a StoryMap; the template for entering data and creating the map was so easy to use almost none of them used the tutorial.)