The emotional lyrics are believed to have been created in response to a letter from Evan's brother urging him to leave Wales and emigrate to the United States.
But the poet stayed in Wales, and before the end of the century the song was being sung all over Wales by soloists and large crowds.
This memorial is in the form of two figures representing poetry and music, and was unveiled by the sculptor, John Goscombe in July 1930. The grave of Evan James is in front of the memorial.
He was reburied in the park in 1973, after Carmel Chapel near Pontypridd, where he was originally buried, was closed and demolished.
'Glan Rhondda', as it was originally called, was first performed in a chapel in Maesteg by Elizabeth John, Pontypridd. It was originally a song in 6/8 time for dancing but was slowed down to its current tempo when crowds started singing it.
The song's popularity increased after the Llangollen Eisteddfod in 1858, when Thomas Llewelyn of Aberdare won a competition for a collection of unpublished Welsh tunes which included 'Glan Rhondda'.
The critic, John Owen (Owain Alaw), asked for permission to include it in his book, 'Gems of Welsh Melody', and this is when it was called 'Hen Wlad Fy Nhadau' for the first time.
At the Bangor National Eisteddfod of 1874, the song became even more famous when it was sung by Robert Rees (Eos Morlais), one of the leading Welsh soloists of the time. Little by little, it was sung at patriotic gatherings and gradually developed into a national anthem even though the official anthem at the time was 'God Bless the Prince of Wales'.
'Hen Wlad Fy Nhadau' was one of the first songs to be recorded in Welsh when Madge Breese sang the song for the Gramophone Company in 1899.
Although 'Hen Wlad fy Nhadau' was not recognised as a national anthem at the time, it was performed at the start of a Wales versus New Zealand rugby match in Cardiff in 1905. The All Blacks began performing the Haka and in response led the Welsh players in the crowd to sing 'Hen Wlad fy Nhadau'. Obviously, this worked, as Wales won 3-0.
In 1977 the Welsh football team staged a protest at their match against England at Wembley when the English Football Association refused permission for 'Hen Wlad Fy Nhadau' to be played before the game. The team decided to sing it themselves, refusing to start the game until they were done.
The following year Geraint Jarman a’r Cynganeddwyr recorded guitarist Robert 'Tich' Gwilym's instrumental version on the album 'Hen Wlad fy Nhadau'.
Petitions to make the song the official national anthem for Wales are occasionally presented to Parliament. Last time, in 2014, an online petition raised enough names to demand a debate but it was concluded that it was not "a possible development at this time".
'Hen Wlad Fy Nhadau' has been adapted to the anthems of Cornwall ('Bro Goth agan Tasow'), Brittany ('Bro Gozh ma Zadoù') and Y Wladfa ('Gwlad Newydd y Cymry'), with these adaptations sharing the same tune and similar lyrics.