Since Charles (Pa) has just been struggling to attach the canvas wagon top over the top of his unroofed house in a strong wind, he is both tired and triumphant when he succeeds. His wife suspects that he is about to say "and be damned!" to the balky canvas. An example of such usage appears in Benjamin Hall, History of Eastern Vermont, volume 2 (1865):
He [the sheriff] then read the riot act to them [the rioters], and ordered them to disperse within one hour, and told them, that if they did not disperse within that time, and cease their opposition to his entrance into the Court House, he would most certainly order the Posse to fire on them; to which they replied 'Fire and be damned! If you do, the hardest fend off.'
Likewise, from Christopher North, "Postscript to the Public" in Blackwood's Magazine (July 1822):
"Must I answer it?" quoth we, mildly. "Answer it, and be damned!" retorted Odoherty; and flinging it, either by accident or design, into the silver coffee-pot, whose mouth we had just opened, to take a peep into the contents, now low as the funds during the mutiny at the Nore, stalked majestically across our study in three strides...
And from Narrative of the Life of Frederick Douglass (1845):
"Shoot me! shoot me!" said Henry; "you can't kill me but once. Shoot, shoot,—and be damned! I won't be tied!' This he said in a tone of loud defiance; and at the same time, with a motion as quick as lightning, he with one single stroke dashed the pistols from the hand of each constable.
And from Andrew Jenson, "The Twelve Apostles" in The Historical Record (December 1886):
Wilson said, "Wight, you are a strange man ; but if you will not accept my proposal, you will be shot to-morrow morning at 8." Wight replied, 'Shoot and be damned.'
And finally, an example where stay precedes the infernal invitation. From Francis Parkman, The Conspiracy of the Pontiac and the Indian War After the Conquest of Canada, volume 2 (1870):
At length, declaring that provisions were failing and the season growing late, he [Colonel Bradstreet] resolved to return home ; and broke up his camp with such precipitancy that two soldiers, who had gone out in the morning to catch fish for his table, were inhumanly left behind; the colonel remarking that they might stay and be damned.