What was the reasoning behind the Homestead Act?

On July 4, 1861 in speaking to a special session of Congress Abraham Lincoln tried to explain what their side was fighting for in the Civil War:

"This is essentially a People's contest. On the side of the Union, it is a struggle for maintaining in the world, that form, and substance of government, whose leading object is, to elevate the condition of men---to lift artificial weights from all shoulders---to clear the paths of laudable pursuit for all---to afford all, an unfettered start, and a fair chance, in the race of life. Yielding to partial, and temporary departures, from necessity, this is the leading object of the government for whose existence we contend."

It can be argued that the passage of the Homestead Act by Congress in the spring of 1862 was an attempt to meet Lincoln’s definition of the “leading object” of our government; that is, in giving away free land through the Homestead Act Congress hoped “to elevate the condition of men---to lift artificial weights from all shoulders---to clear the paths of laudable pursuit for all---to afford all, an unfettered start, and a fair chance, in the race of life.”

Other Presidents have agreed on the purpose of the Homestead Act:

• Lyndon B. Johnson, August 26, 1965: Like the lawmakers in our past who created the Homestead Act….we say that it is right and that it is just, and that it is a function of government, and that we are going to carry out that responsibility to help our people get back on their feet and share once again in the blessings of American life.

• George H.W. Bush, November 28, 1990: Abraham Lincoln's Homestead Act empowered people; it freed people from the burden of poverty. It freed them to control their own destinies, to create their own opportunities, and to live the vision of the American dream.

• George W. Bush, January 20, 2005: In America's ideal of freedom, citizens find the dignity and security of economic independence instead of laboring on the edge of subsistence. This is the broader definition of liberty that motivated the Homestead Act, the Social Security Act, and the GI Bill of Rights.
  
  

However, others would argue the motivation behind the Homestead Act was “Manifest Destiny.”

Manifest Destiny was the belief that the people of the United States were destined to extend the "boundaries of freedom," democratic institutions, and American ideals from the Atlantic seaboard to the Pacific Ocean.

Still others would argue the motivation behind the Homestead Act was greed; that Eastern capitalists wanted to see the West settled so there would be an expanding market for the products of industrialization.

What do you feel was the reasoning behind the Homestead Act?