Samaria was populated by a remnant of Jews from that area who had inter-married with those from foreign nations relocated there by the Assyrians. Galilee, according to the Jewish historian, Josephus, was repopulated by Alexander Jannaeus, king of Israel (102-76 B.C.), who extended his kingdom to include Galilee. Apparently Jannaeus controlled Samaria as well, but was unable to reestablish it as a purely Jewish province. Detested as they were, still the Lord used Samaritans as "heroes" for His teaching (Lk. 10:30-37; 17:12-19; Jn. 4:-42).
"The Great Commission," Matthew 28:19-20, Mark 16:15, and Acts 1:8, was to start where they were, and to go until the whole world had heard the Gospel. As I write this, His command to spread the Gospel is losing ground to population growth, to cults, and other religions. The percentage of professing Christians today is considerably smaller than it was in the 1800's. And, when one considers that there are far more "professing Christians" (religious, but unsaved - tares) than there are "possessing Christians" (born again believers - wheat), there is really no way to tell how many true believers there really are. Remember, a count of religious adherents includes children in families, but being a member of a family does not make one a member of His family!
It would be easy to get discouraged and give up. But God's Word says, "But ye, brethren, be not weary in well doing" (2 Thes. 3:13). God does not expect to win the world to Christ; He just expects us to be found faithful when He returns for us! We may not be able to go to the ends of the world ourselves, but because of the Internet, Facebook, satellites, etc., we can, and must, proclaim the Gospel while we still have time. Paul wrote, "Walk in wisdom toward them that are without, redeeming the time (Col. 4:5).
Time may not be on our side, but the Time-keeper is!