Complex sentence: Little did not explain exactly when Josiah Wright Mather made this claim-but it is at odds with Josiah's telling his children that he never saw his brother again after they left Dodge City in 1885, or learned what happened to him.
Split into simpler sentences: Little did not explain exactly when Josiah Wright Mather made this claim. It is at odds with Josiah's telling his children that he never saw his brother again after they left Dodge City in 1885, or learned what happened to him.