The Morrill Act, signed into law by Abraham Lincoln on July 2, 1862, set aside public lands for the establishment of land-grant universities. The act came from a movement favoring practical scientific and industrial education for American working classes. Led by Congressman Justin Morrill of Vermont, the land-grant idea emerged as a reaction against the classical curriculum that dominated traditional institutions. Sparked by advancements in science prior to 1850, reformers sought a system that could build upon the resourcefulness of industrial classes. Morrill, himself the son of a blacksmith, believed in better educational opportunities for the children of artisans, farmers, and laborers. He believed that a true democracy meant educating everyone, not just those who sought careers in law, politics, and the ministry. Morrill was also influenced by a crisis of declining agricultural productivity on American farms. He learned about the advances in scientific agriculture in Europe and believed that similar practices could be applied in the United States, especially as it expanded westward into new agricultural areas. The Morrill Act was passed the same year as the Homestead Act, thus further encouraging agricultural development in the Great Plains.

President James Buchanan had vetoed Morrill's first land-grant bill in 1857 on the grounds that higher education should be left to the states. Morrill was also hindered by southerners' skepticism of the expansion of federal powers and the bill's perceived favoritism toward northern states and territories. After the Civil War began, Morrill introduced the bill again in 1861 to a more receptive, northern Congress. Morrill set aside for every state the sale of 30,000 acres for each representative and senator to endow and support land-grant universities. The act allowed for teaching a classical curriculum, but the emphasis was on agriculture, mechanical arts (engineering), and military tactics. Ironically, western states that later benefited from the Morrill Act were some of its loudest detractors in the beginning. Westerners feared that all of the public lands would be taken from their states. Kansas senator James Lane offered an amendment that limited the land claimed in any one state to one million acres. With that amendment, the bill was passed.

During the Civil War, only two states, Iowa in 1862 and Kansas in 1863, passed land-grant resolutions. Not until after 1865 could most states refocus their attention on higher education. Kansas was the first Plains state to take on the conditions of the Morrill Act, with the Kansas State Agricultural College (Manhattan), founded in 1863. Nebraska was next, with the University of Nebraska (Lincoln), founded in 1869. Other Plains states and territories followed, with Texas A&M University (College Station) in 1876; Colorado State University (Fort Collins) in 1879; South Dakota State University (Brookings) in 1881; the University of Wyoming (Laramie) in 1887; North Dakota State University (Fargo) in 1890; and Oklahoma State University (Stillwater) in 1890. Since the land-grant universities were founded to be the agriculture and mechanical schools, some states established separate state universities with an emphasis on liberal arts. Kansas, Oklahoma, and South Dakota, for example, each established two universities, one land-grant and one state university. Nebraska and Wyoming combined both the land-grant purpose and liberal arts into one consolidated university.

The land-grant curriculum focused on practical, scientific education. Besides mechanical arts, the curriculum could include agriculture, pharmacology, and, for women, domestic economy. Military training was also required of male students, and many of those soldiers and officers later served in the Spanish-American War and both world wars. In the Great Plains, institutions focused on agricultural studies, which included efficient crop production, animal science, dairying, and plant biology. In the twentieth century, agriculture science expanded to include genetics, hybridization, fertilizer production, and veterinary medicine. Women were included in the land-grant mission through domestic or home economics programs, because efficient farms also needed educated farm wives.

Land-grant universities were progressive not only in their approach to practical education but also because they admitted women and people of color; all students received free tuition and subsidized rail travel. These institutions struggled financially and academically before 1900, and some critics claimed that young people never returned to farm work after attending college, thus defeating the very purpose of the land-grant mission. Even if that was the case, land-grant institutions continued to reach out to rural, agricultural populations. In 1887 Congress passed the Hatch Act to stimulate research in agriculture science through the creation of experiment stations at which students and professors could apply new knowledge toward efficient farm production. Students even lived and worked on model farms that allowed them to use their classroom education in a working and productive farm setting. The Hatch Act expanded the role of land-grant universities through research contributions to agricultural science that continue to this day.

In 1890 the second Morrill Act was passed, providing additional land-grant endowments. States that made distinctions of race in admissions could not receive the funds, so the act allowed for the creation of separate land-grant universities for blacks. The founding of many all-black colleges after 1890 included two in the Great Plains: Prairie View a&m University in Texas and Langston University in Oklahoma. All other Plains land-grant institutions continued to admit black students. It was not until 1994 that Congress passed the Equity in Educational Land-Grant Status Act, which created land-grant colleges for Native American populations. Plains states benefited most from this, with a majority of Indian landgrant colleges located in South Dakota (four), North Dakota (five), Montana (seven), Nebraska (one), and Kansas (one).

The desire to extend land-grant education to a broader population led to the creation of the Cooperative Extension Service as part of the Smith-Lever Act of 1914. Because practical education was still unavailable to many, cooperative extension sought to disseminate information to a wider population, especially in agriculture, home economics, and rural energy. Extension programs especially benefited Plains states, with their large geographic areas and scattered rural populations. Today, extension programs continue to take education to distant farm areas.

In the twentieth century, land-grant universities expanded their missions beyond the agricultural scope of the nineteenth century. Not strictly agriculture and mechanics schools anymore, land-grant universities also developed arts, humanities, and social science programs. Graduate programs were established in most departments on land-grant campuses. Further, land-grant universities endeavored to carry on in their purpose of providing public, democratic, and practical education to a larger population. Broad admissions standards, low tuition costs, cooperative extension programs, and agricultural experiment stations are some of the methods used by landgrant institutions to make education widely available to many in the Great Plains.