Final answer:
The Morrill Acts of 1862 and 1890 provided for the creation of public colleges/universities in established states.
Step-by-step explanation:
The piece of legislation that provided for the creation of public colleges/universities in already established states was the Morrill Acts of 1862 and 1890. These acts set aside public land and federal funds to create land-grant colleges that were affordable to middle-class families. These colleges focused on offering courses and degrees useful in various professions, as well as in trade, commerce, industry, and agriculture. They aimed to provide an affordable college education, leading to a boost in enrollment from 50,000 students nationwide in 1870 to over 600,000 students by 1920.