Thayer, Kansas came into existence in 1870 with the arrival of the L.L.& G. Railroad. The townsite was selected by a private corporation by men connected with the railroad, for the purpose of selling lots and land.

There is some question whether Thayer was named in honor of Eli Thayer, a congressman from New England who started the Kansas Crusade which did much to advance the early settlement of the state; or whether it was named in honor of Nathaniel Thayer, a financier of the railroad company that started the town. Both were great men. The circumstances of the naming indicates that Nathaniel Thayer was the one after whom the town was named.

The temporary terminus of the L.L. & G. Railroad attracted big numbers of laborers and traders. This was the most advanced railroad in the country and merchants came from far and wide to get their merchandise which had been freighted to this point. The population grew to 600 in six months and over 200 guests took breakfast one day at the Baldwin House, conducted by General Darr.

L.L. & G. Railroad was finished to Thayer in the autumn of 1870 and that town remained terminus for some months. The press for lots became a stampede, especially for desirable business lots, and everybody wanted to build at once. Houses went up with a rush, carpenters and other mechanics were in demand and the capacity of the railroad was taxed to bring in the merchants there and points tributary thereto. It is estimated that the population reached 1000 that winter, with few women among the inhabitants.

A large number of people at Thayer that winter were men who were anxious to go to work on the construction of the extension of the railroad and many of them were of the roughest make, with boisterous ways and addicted to the use of intoxicants

An act of congress, approved April 19, 1871, granted permission to the L.L. & G. Railroad Company to relocate its route south of Thayer. Soon after this, the railroad resumed its building south towards Coffeyville, and Thayer’s boom soon deflated. The reaction was strong, and it is said the population dropped to 300. But the rabble was gone, and those who remained were of sterner stuff, and they set about building a good, wholesome community which any good citizen would be pleased to call his home. Thayer was transformed into one of the most law-biding communities in Neosho County.

Thayer is said to be located up on the highest level prairie in Neosho county. Several Streams have their origin in the Thayer vicinity, some of the drainage going to the Neosho river and some to the Verdigris.