What is so hard for you to comprehend that most of those territories were barren and unpopulated in 1861 and that those states on the west coast from 1861 all went to Kerry?
Sparsely populated, yes. "Barren and unpopulated," no.
By way of example, Florida in 1860 had a free population of fewer than 80,000.
Colorado Territory - 34,300
Nebraska Territory - 28,800 (statehood in 1867)
New Mexico Territory - 95,500 (comprising New Mexico and Arizona, separate Arizona Territory created by Congress in 1863)
Utah Territory - 40,000 (parts of Colorado and Wyoming)
Dakota Territory - 4,800 (comprising N. and S. Dakota, parts of Wyoming and Montana)
Nevada Territory - 6,900 (from Utah territory in 1861 during silver rush - statehood in 1864)
Washington Territory - 11,500 (included Idaho and parts of Wyoming)
You can see that your "unpopulated" statement is bunk.