The green or summer squash is best when the outside is beginning to turn yellow, as it is then less watery and insipid than when younger. Wash them, cut them into pieces and take out the seeds. Boil them about three-quarters of an hour, or till quite tender. When done, drain and squeeze them well till you have pressed out all the water; mash them with a little butter, pepper and salt. Then put the squash thus prepared into a stewpan, set it on hot coals and stir it very frequently till it becomes dry. Take care not to let it burn.
Summer squash is very nice steamed, then prepared the same as boiled.
The Whitehouse Cookbook, by Mrs. F.L. Gillette (Year 1887)