Thwaites discovered and uncovered various additional original sources, including the journal of Charles Floyd, the only member of the Corps of Discovery to die on the expedition.

[12][13] His summaries include phraseology such as "[Europeans] left the most luxurious country in Europe to seek shelter in the foul and unwelcome huts of one of the most wretched races of man.

"[14] When editing the Jesuit Relations, he included background information that is generally credible and thorough with respect to events and Europe, but is far less thorough in regard to the disruptions from disease and other sources that the indigenous people themselves were facing.

[15] In other words, the criticism is that the original works were insensitive, and Thwaites failed to fully account for the prejudicial and inaccurate reporting in the Relations.

However, Thwaites is also recognized as being the pioneer in an approach to using the Relations that is continuing to be enriched by modern scholarship, and so in a sense he started a process by which his very work could be corrected and improved as historians learn more about the periods in question.