This paper reports the results of a multi‐phased investigation into Open Government Data (OGD) sites in the United States. Upon searching and examining OGD sites by state and state capital, we outlined current OGD practice in the US. An inventory of data processing capabilities of 50 OGD sites uncovered the most frequently occurring data categories, search and filter options, raw datasets, data visualization displays, data extraction formats, interactive and map tools, and help functions provided through the OGD sites. Heuristic evaluation of 15 sites containing “Transportation” datasets revealed that main usability problems were violations to the principles of “Flexibility and Efficiency of Use,” “Help and Documentation,” and “Help users to recognize, diagnose and recover from errors.” Findings suggest that in order to sustain and achieve a good usage of OGD sites, a significantly better understanding of user populations, their data needs, and their data literacy levels is needed.