1873 30 Oct. 186/2 A letter A tent is the greatest luxury in camping, but in fair weather a tilt or half tent of canvas or blankets, or a ‘rough slant’ of bark or boughs.., are comfortable enough.
1878 C. Hallock (ed. 4) Gloss. p. x/1 Rough-slant, a lean-to; a shelter made of canvas, blankets, bark, or boards, laid on poles supported on crotches, and sloping from a ridge-pole to the ground.