This work is dedicated to Antanas Karolis Giedraitis (Antoni Karol Giedroyć, A.K. Gedroïz, А.K. Гедройц) (1848–1909) geological research that he did in Lithuania territory for geological mapping. In the History of Science, A.K. Giedraitis is called the first professional geologist of Lithuania, who investigated geology of our and neighboring countries. In 1895 he compiled a geological map of very large territory – Russian Empire governorates of Vilnius, Kaunas, Suvalkai, Gardinas, and Minskas according to international standards. It is important to understand A.K. Giedraitis’ approach to the formation of Quaternary sediments and the theory of polyglacialism. He took at that time the bold position that this entire region two or even three times had been covered by a glacier that advanced from the North. Based on the weathering (wearing) of erratic boulders and glacial incisions, he tried to describe the limits of glacier expansion and the directions of its movement. A.K. Giedraitis’ professional achievements are well-known, they are evidenced by the detailed reports and publications of his geological research in German, Polish, and Russian, which were published in 1886, 1887, and 1894. A summary of all his research was published in 1895, together with a geological map to a scale of 1:420 000. Interestingly, research carried out nowadays has confirmed some of the more than 130-year-old insights of A.K. Giedraitis about the geological formation of our country.