historydata: Data Sets for Historians
From the webpage:
These sample data sets are intended for historians learning R. They include population, institutional, religious, military, and prosopographical data suitable for mapping, quantitative analysis, and network analysis.
If you forgot the historian on your shopping list, you have been saved from embarrassment. Assuming they are learning R.
At least it will indicate you think they are capable of learning R.
If you want a technology or methodology to catch on, starter data sets are one way to increase the comfort level of new users. Which can have the effect of turning them into consistent users.