There are many data sources freely available once you achieve a certain level of data literacy and graphicacy. IPUMS is a curated collection of census and survey data critical for comparative research of individuals, families, or communities.
One of the advantages of IPUMS is the weighted data provided. For example, in a given data sample, each singular person in a "flat" or unweighted file represents 100 people.
In the weighted files, individuals are not represented as 100 people but their actual representation in the general population is provided.
The Tableau story below is being created to help guide an audience through data exploration using visualization. It is a rough depiction of how visualizing data can be instrumental in generating hypothesis.
In honor of Black History month, I visualized data from the 1850s and 1860s regarding the US slave population. Once the presentation is live I will be happy to post--but for now you can view the story as a stand alone collection of visualizations meant to suggest opportunities for additional exploration.