Aunt Docia “was angry because Uncle Hi had worked hard all summer and had nothing to show for it.’He’s worked like a nailer all summer!’ she said. ‘He’s even worked his own teams on the grade, and both of us saving and scrimping and pinching till the job was finished, and now it’s finished and the company says we owe them money! They say we’re in debt to them for our summer’s hard work! And on top of that they want us to take another contract, and Hi takes it! That’s what he does! He takes it!’” (By the Shores of Silver Lake, Chapter 5, Railroad Camp”)

A nailer was a smith who made nails. A diligent nailer could perhaps make two thousand nails in a day. In SSL, Wilder may be implying that Uncle Hi worked hard at doing one specific task all summer, like a nailer. She may simply be implying that he worked hard.

The published phrase – “work like a nailer” – isn’t used in either Pioneer Girl or the existing manuscript for By the Shores of Silver Lake. In the book manuscript, Uncle Hi “has worked since spring running this camp. He has hired drivers and worked his own teams on the grade. He has been careful of expenses and done a good job of work and he gets less than nothing for it all.” In Pioneer Girl, Uncle Hi had spent a “hard summer’s work.”

It’s not known when the phrase was added, but it’s entirely possible that the original had been “work like a nigger,” since this (as well as “work like a horse”) were commonly in use at the time the “Little House” books were written, and Wilder did use the word “nigger” in both Pioneer Girl and in her manuscripts.