What is the basic unit of length used in the public land survey?

The basic unit of length used in the public land survey system is indeed Gunter's chain, which measures 66 feet or 100 links. This unit was developed by Sir Edwin Gunter in the early 17th century and is critical for land surveying practices in the United States. The use of this chain allows surveyors to measure distances accurately in the field and is integral to the rectangular survey system, which divides land into townships and sections.

Gunter's chain is especially significant in the context of the public land survey because it addresses the need for a standardized measuring tool that can be easily used with the concept of a section being one mile square, which equals 640 acres. This connection with the public land survey system emphasizes the importance of Gunter's chain in determining property lines and boundaries through systematic plotting.

The other options do not align with the basic unit of length used in this surveying practice. The meter, while a universal standard of measurement in many contexts, is not utilized within the public land survey framework. The square root and square mile refer to area or mathematical concepts rather than linear measurements, making them irrelevant in this context. Understanding the historical and practical relevance of Gunter's chain helps clarify its role in land surveying processes effectively.