Complex sentence: There are no verbatim transcriptions of Henry's speech in opposition to the Stamp Act are for the most part based on recollections decades later by which time both the speech and Henry had become famous.
Split into simpler sentences: There are no verbatim transcriptions of Henry's speech in opposition to the Stamp Act. Texts are reconstructions, for the most part based on recollections decades later by which time both the speech and Henry had become famous.