Why were glass windows so expensive when Laura was a girl?

He drank his coffee and wiped his mustache with his handkerchief, and said: “Ah! That hits the spot, Caroline! Now I’m beginning to thaw out.”

Then his eyes twinkled at Ma and he told her to open the square package on the table. “Be careful,” he said. “Don’t drop it.”

Ma stopped unwrapping it and said: “Oh, Charles! You didn’t!”

“Open it,” Pa said.

In that square package there were eight small squares of window-glass. They would have glass windows in their house.

Not one of the squares was broken. Pa had brought them safely all the way home. Ma shook her head and said he shouldn’t have spent so much, but her whole face was smiling and Pa laughed with joy. They were all so pleased. All winter long they could look out of the windows as much as they liked, and the sunshine could come in.

Pa said he thought that Ma and Mary and Laura would like glass windows better than any other present, and he was right. They did.

• Little House on the Prairie, Chapter 17, Pa Goes to Town

In Little House on the Prairie, Charles brings back 8 panes of glass so that they could have real glass windows in their new log cabin.  It had been mentioned previously in the book, but Caroline was concerned about the expense, especially as the Ingalls always seemed to be short of money.

Many pioneer homes did not have glass windows, so it wasn’t unusual that they did not have glass initially. Glass was expensive and difficult to transport to remote areas, so pioneers often used alternative materials such as oiled paper, cloth, or animal skins to cover windows. They also sometimes used wooden shutters or boards to cover windows at night or during inclement weather, which Laura had specifically mentioned in Little House in the Big Woods where they had both glass windows and shutters to protect them and help with keeping the heat in.

It was more common for wealthier settlers or those who settled in more established areas to have glass windows in their homes, which is also why most of the homes in De Smet had glass windows.

When they left their log cabin on the prairie in Little House on the Prairie, it is unclear why the Ingalls left something so expensive behind and did not at least try and travel with some of the glass.