This is a series of articles available through the Church History website for the Martin Handcart Company
These articles show the commitment of the church to embrace its history, as it includes negative comments as well as positive. It has a new story based on an ex "Elder" saying the deaths prove Brigham Young was not a prophet. Another is a very graphic description of the handcart pioneers published in a New York newspaper. It also has the description from the Deseret News. There are also official publications from "The Mormon" church publication in New York. There is a powerful discourse from Brigham Young. There is one article I hoped would be available. This is the conference discourse of President Young that is quoted in the Hafen book.
Very useful series of articles