Complex sentence: Both claims were widely debated in newspapers until 1913; modern historians generally think Cook did not reach the pole, and there are grave doubts that Peary did, though he may have been as close as.
Split into simpler sentences: Both claims were widely debated in newspapers until 1913; modern historians generally think Cook did not reach the pole. There are grave doubts that Peary did, though he may have been as close as.