The rectangular system of public land surveys over the public domain provides a simple and certain form of land identification and legal description. It has been used continuously since 1785. Although few of the original surveys now being made cover extensive areas, except in the State of Alaska, all facets of the rectangular system occasionally come into use. For this reason, and to make clear the procedures that have been followed in surveying public lands, a complete discussion of the system is included in this course. The field procedures outlined in this course include procedures used historically as well as current methods for conducting an original survey. Historically, original surveys were made to create surveys of new areas by extending existing rectangular surveys in to unsurveyed lands. This approach differs from the modern practice of using a protraction diagram or predetermined plan of survey so new surveys can be made in areas where they do not necessarily adjoin existing rectangular surveys. Other procedures discussed in this course include creating protraction diagrams, special instructions diagrams where no protraction exists, and modifying approved protraction diagrams. This is a 10 hour online continuing education course for Land Surveyors.