[citation needed] In early youth he worked on a farm, attended and taught school, studied engineering, and became interested in American antiquities.

[4] Among Squier and Davis's most important achievements was their systematic approach to analyzing and documenting the sites they surveyed, including the Serpent Mound in Peebles, Ohio, which they discovered in 1846.

They also mapped the Mound City Group in Chillicothe, Ohio, which has been restored using their data and is now part of Hopewell Culture National Historical Park.

[5] Squier was appointed special chargé d'affaires to all the Central American states in 1849, and negotiated treaties with Nicaragua, Honduras, and San Salvador.

In 1853, he made a second visit to Central America to examine a line for a projected interoceanic railroad, and to make further study of the archaeology of the country.

[1] Besides many official reports, scientific papers, magazine articles, and contributions to the Encyclopædia Britannica and foreign periodicals, his works include: