Land Titles & Deeds
Land Grants and Land Patents are Contracts for Conveyance of Land Titles. The highest title to land in the United States is a Government grant, a patent either from the National Government or a State.  A Government grant for land has been, and is held to be, "a contract executed." (Fletcher v. Peck, 6 Cranch, 87.)

Asserting Your Rights As A Land Holder - This document gives a practical understanding and use of an "Declaration of Land Patent" to oppose unconstitutional and unlawful taxation, regulation or taking of one's land property.

Texas Government Land Office:  http://www.glo.texas.gov/what-we-do/history-and-archives/our-services/index.html These fine folks archive and have friendly search engines to locate your patent or grant which should be stipulated on your survey abstract number .  It should tell you what the Abstract Number is in the County where the Land is located. 

http://www.glo.texas.gov/cf/land-grant-search/index.cfm   has a great search tool, and has free downloadable PDF documents.  From there, you can order a Certified copy of the Land Patent or Grant your land is on.  If a Mexican or Spanish Land Grant, you will need to order a translation of the Grant as well, as no county will record one in the Spanish language. There is a fee for this service.

GLO also provides Services, such as Land Classification Letters, which tell what minerals were reserved for the STATE OF TEXAS, if any, and a Certificate of Fact which gives the Chronological history of your land, from the Certificate being issued, the survey being done, and the Patent or Grant being issued.

Patent / Grants / Allodial Title Thomas Jefferson's Letter to Edmund Pendleton August 13, 1776
"The opinion that our lands were Allodial possessions is one which I have very long held, and had in my eye during a pretty considerable part of my law reading which I found always strengthened it."

Warranty Deeds / Deeds of Trust /
Quit Claim Deeds / Quiet Title
Sheriff's Deeds /
Restrictions / Reservations Kept
Minerals / Water / Riparian / Easements & Right of Ways / Cemetery Right of Ways
Resources: GLO Office, 4 Audio Lectures from Mike Palma,