The first Republican platform was much shorter than modern platforms, so you may want to read the whole thing.  If not, here are some samples:

This Convention of Delegates, assembled in pursuance of a call addressed to the people of the United States, without regard to past political differences or divisions, who are opposed to the repeal of the Missouri Compromise; to the policy of the present Administration; to the extension of Slavery into Free Territory; in favor of the admission of Kansas as a Free State; of restoring the action of the Federal Government to the principles of Washington and Jefferson; . . .
. . .
Resolved, That the Constitution confers upon Congress sovereign powers over the Territories of the United States for their government; and that in the exercise of this power, it is both the right and the imperative duty of Congress to prohibit in the Territories those twin relics of barbarism—Polygamy, and Slavery.
. . .
The right of the people to keep and bear arms has been infringed.
. . .
Resolved, That a railroad to the Pacific Ocean by the most central and practicable route is imperatively demanded by the interests of the whole country, and that the Federal Government ought to render immediate and efficient aid in its construction, and as an auxiliary thereto, to the immediate construction of an emigrant road on the line of the railroad.

Resolved, That appropriations by Congress for the improvement of rivers and harbors, of a national character, required for the accommodation and security of our existing commerce, are authorized by the Constitution, and justified by the obligation of the Government to protect the lives and property of its citizens.

The 1856 Republicans were opposed to slavery, in favor of traditional marriage, supporters of the 2nd Amendment, and supporters of improved transportation networks.  The 2008 Republicans would probably agree with their predecessors on all those points.

By way of contrast, here is the 1856 Democratic platform.  What struck me most about it was how imperialist the 1856 Democrats were.  For example, they believed that the United States should control Panama, and say so in high-flying prose.

Cross posted at Jim Miller on Politics.

(I corrected an obvious typo in the on-line Republican platform.

You can find the major party platforms, including the latest, here)