I cannot enumerate the number of contexts in which I have seen, or the crazy statements rationalized by, the statement that photography was struggling to be recognized as a True Art. It is used to justify things people do and say today as if the question were still open. It is used, quite a lot, to justify why the speaker is having trouble getting in to Art Galleries.
It's why Adams has to rage against Mortenson, it's why Pictorialism had to arise, it why Pictorialism had to be destroyed. It's used to justify and explain anything and everything. It's also completely wrong.
To be sure, there have always been and always will be voices that claim photography is not Art, whatever that statement might even mean. But the battle was over and won before the year 1900. Robinson and his crew put the spear into it in Europe, and Stieglitz did the same in the Americas not much later. Nobody thought Photography was Painting, any more than they thought it was Sculpture, but it was certainly an Art.
There were certainly questions about how one ought to go about it. Which processes were better than others? Should one hand work or not? These questions roiled from the very beginning. Well, at least starting from the moment there was more than one process to chose from. The acceptance as An Art was gradual, but essentially complete by 1891. PH Emerson (having been on the opposing side for decades) suddenly switched sides and declared photography to be Not An Art at all, just in time to be once again in disagreement with the establishment.
Across the water, in the twenty years following, Stieglitz did "Camera Work" and the 291 gallery, the MOMA started showing photography by its 16th exhibition, in 1932, and never much altered the pace at which it shows photographic Art thereafter.
The anti-pictorialism displayed by f/64 wasn't about Art at all, it was about trying to get Stieglitz' attention, partly by pissing in his breakfast cereal and partly by loudly being a Western avant garde.
Photography is an Art. It's been an Art for more than 100 years. Anyone who claims otherwise is trying to sell something.