In April 1940 Denmark got occupied by Germany and the connections
between Denmark and Greenland were broken.
The Danish representative in Greenland, Henrik Kaufmann made
an agreement with the United States of America to let Greenland
be protected by USA, while Denmark was occupied.
During the 5 years the occupation of Denmark, Greenland got its
stamps printed in the United States of America.
This series of stamps is like the rest of the stamps from Greenland
very beautiful and besides they are pretty rare.