  We re-examine the common narrative that a 1941 experimental error by
physicists Walther Bothe and Peter Jensen led Germany to abandon graphite as a
reactor moderator during World War II. We first detail the history of both
German and American graphite experiments, noting that the Americans faced
similar setbacks but succeeded only at the end of a costly 18-month graphite
purification program. We then use Monte Carlo N-Particle simulations to
reconstruct Bothe's 1941 experiment. We find the thermal absorption cross
section of Bothe's Siemens electrographite to be 12.2 mb, in contrast to his
reported 7.9 mb. This discrepancy arises because the neutrons in Bothe's
experiment did not reach thermal equilibrium, leading to an underestimation of
neutron absorption. Additionally, despite misconceptions that the Germans were
unaware of boron impurities, we share evidence that Wilhelm Hanle accurately
measured boron and cadmium impurities in the electrographite. To support our
findings, we provide 9 excerpted and 3 complete English translations of
classified wartime reports by Heisenberg, Joos, Bothe, Jensen, H\"ocker, Hanle,
and Kremer. Our work aims to illuminate the rational constraints behind
Germany's decision to forgo graphite moderation.
