The more he struggled to get free, the deeper he got in.

Jonas stepped on before him, and patted him on the head, and tried to quiet him.
"Jonas," said Oliver, "let us stop; I don't believe we can go any farther." "Nor I," said Jonas.

"At least I don't think we can get the old General any farther." "Nor back again either," said Oliver, "as I see." The boys stood still, looking upon the horse a moment, utterly at a loss what to do.
"Oliver," said Jonas, "should you be willing to stay here and take care of the horse, while I go on and see about the logs ?" "Why--I--don't know," said Oliver.

"I'm afraid he won't stand quiet." "O, I shall get him out of the snow, first," said Jonas, "and take him to some level place, where he'll stand well." "How shall you get him out ?" asked Oliver.
"Why, we will unharness him first," said Jonas, "and then draw the sleigh back out of the way." So Jonas began to unbuckle the straps of the harness, in order to liberate the horse.

Oliver tried to help him, but he could not do much, the horse was so deep in the snow.