In 1881, he was detailed as first sergeant for the Lady Franklin Bay Expedition, which was commanded by Adolphus Greely. Over the three years of this expedition he continuously kept a journal.
Twenty-five men began the expedition, which ran into difficulty when several attempts to resupply it failed, and several rescue attempts were forced to turn back. Among those who died was James Booth Lockwood, second-in-command and Brainard's companion on many excursions, including their record breaking push north to latitude 83°23 '30". Brainard wrote:
Lieut. Lockwood became unconscious early this morning and at 4:30 p.m. breathed his last. This will be a sad blow to his family who evidently idolized him. To me it is also a sorrowful event. He had been my companion during long and eventful excursions, and my feeling toward him was akin to that of a brother. Biederbick and myself straightened his limbs and prepared his remains for burial. This was the saddest duty I have ever yet been called upon to perform.
Brainard was later credited with preventing the deaths of everyone on the expedition by closely rationing its limited food. Shortly before the survivors were rescued in the spring of 1884, Brainard, freezing, starving, and suffering from scurvy wrote: "Our own condition is so wretched, so palpably miserable, that death would be welcomed rather than feared …"Brainard was one of only six survivors rescued by Rear Admiral Winfield Scott Schley on June 22. On that day, he was reportedly near death himself, too weak to hold a pencil so he could make an entry in his log
https://thereaderwiki.com/en/David_L._Brainard
General_David_L_Brainard_U_S_Army_Last_Survivor_of_the_United_States_Lady_Franklin_Bay_Expedition_1881_84_
"On April 14, Greely wrote in his journal that Brainard was to succeed him in command of the expedition
should anything happen to him. On April 22, Greely added, 'I gave Sgt. Brainard instructions about my
effects &c. if anything should happen to me. I want Brainard commissioned.' The stalwart Sergeant
was making two and three trips a day to the tidal crack to net small crustaceans referred to as "shrimps";
he often returned to camp dizzy and staggering. Brainard earned an officer's commission many times
over during the expedition.
Not everyone in camp was concerned with the party's general welfare. Pte. Henry was warned more
than once about repeatedly stealing food and on the evening of June 5, Greely quietly ordered that
Henry be shot if he was again caught stealing food. Henry was caught yet again, and Greely wrote a
new order to Sergeants Brainard, Long and Frederick–execute Pte. Henry. The three executioners drew
lots as to who would fire the shots, as there was only one suitable rifle in camp, and swore never to reveal
the man's name. Henry then paid the ultimate price for his crime. "
https://littlebighorn.info/Articles/Bio-GeneralBrainard.pdf