The U.S. Senate approved the purchase of Alaska from the Russian Empire on March 30, 1867, for $7.2 million. That was about at about two cents per acre.
The intention was to form a US territory and later a State, if an electorate could be found. In fact, the human population of Alaska was very small and mostly Mongolian and Russian fur trappers; and the local Eskimo [Innuit].
The Senate commissioned a census of US citizens in the new territory and the report was zero. That may not have been the case; only that they were so spread out in the vast area that they could not constitute an electorate at that stage.
In the two previous major territorial acquisitions (Louisiana by purchase, and Texas by invasion), Senate determined that an early record of the population should be made. Alaska was seen as another case for the same approach.
Although he had been assassinated two years before, the caricature of Lincoln is used because he had the most easily recognised appearance of all US politicians at the time. President Grant would not have been recognised so well by most people, and certainly not in the outside world.