What Is The Origin Of The Phrase 'An Ugly Duckling'?

'Ugly Duckling' is a phrase that is often used contemptuously for a person who lacks physical charm or appearance at a young age but becomes beautiful at growing up.
The actual origin of this phrase comes from the time of Hans Christian Anderson. 'The Ugly Duckling' is actually the title of one of his stories.

In the 'Ugly Duckling', a Duck hatches her eggs and when the fledglings come out, is frustrated to see that one of them is not beautiful at all. He is relatively uglier then the other chicks. Because of his poor looks, he is laughed at by his siblings, and those others around him. The Duck mother refuses to accept him as a son, as it disgraces her.
The lonely duckling wanders off alone and without protection. He faces the life as it is, alone.

Finally, the duckling starts growing up, and all creatures are astounded by the beauty of what the ugly duckling grows into a Swan. It turns out that the ugly duckling was only a Cygnet, who grew up, with the taunts of his family, into a beautiful Swan. This story gives a lesson that everything is not what it seems to be, and at times a beautiful heart may be found behind an ugly face.