A generation before the Gold Coast became Ghana, local photographer J.K. Bruce-Vanderpuije opened a small studio in the then-colonial capital Accra, where his family would become the de facto visual historians of a nation that had not yet been born.

For 100 years, three generations of Bruce-Vanderpuijes have painstakingly amassed the world's largest collection of 20th century Ghanaian photographs under one roof. They believe their Deo Gratias photo studio is the oldest in West Africa.

From glass plates to digital files of nation-shaping events to intimate personal portraits, the family's 50,000-image archive offers a unique glimpse into Accra's transition from a colonial port into a bustling modern metropolis.

"The story they tell is that of [Ghana's] history," said Kate Tamakloe, Bruce-Vanderpuije's granddaughter and keeper of the modern archive. "Without a history you have no future."

Virtually unchanged since opening in 1922, Deo Gratias sits on a busy street in the heart of Jamestown, the capital's oldest district. Grainy archive photos reveal the area was once much quieter, before traffic and billboards clogged the streets.

Today, the faces of local families, as well as famous musicians, politicians and patrons adorn the studio's walls. A black-and-white photo of Kwame Nkrumah, Ghana's first leader on gaining independence in 1957, hangs near others of Britain's Queen Elizabeth and disgraced American president Richard Nixon.

"Pictures speak tonnes, louder than what has been written," said Daniel Tetteh, a Ghanaian historian who volunteers with Deo Gratias as an archivist. "If we don't preserve them, it means that the nation will lose its memory."

Tamakloe took over Deo Gratias when her father Isaac Bruce-Vanderpuije, a lifelong photographer who inherited the studio from his father J.K., began to lose his eyesight. What began as a mission to digitise the archive has since become a full-time job, one she hopes to pass onto the next generation when the time comes.

Seated in a lush garden outside the capital, Kate and Isaac flipped through an album of their favourite prints. One showed J.K. elegantly perched atop a race horse. Another showed a young and beaming Isaac aiming his camera towards an unknown subject.

"One must feel proud that for 100 years something has been preserved, and the coming generation will see what's happened," he said, gripping his cane while Kate looked on with a smile. "And I think that is not the end."

(Editing by Alessandra Prentice and Alexandra Hudson)