Daguerreotype
It is said that Daguerre has found the means to collect, on a plate prepared by him, the image produced by the camera obscura, in such a way that a portrait, a landscape, or any view, projected upon this plate by the ordinary camera obscura, leaves an imprint in light and shade there, and thus presents the most perfect of all drawings ... a preparation put over this image preserves it for an indefinite time ... the physical sciences have perhaps never presented a marvel comparable to this one.
A further clue to fixing the date of invention of the process is that when the Paris correspondent of the London periodical "The Athenaeum" reported the public announcement of the daguerreotype in 1839, he mentioned that the daguerreotypes now being produced were of considerably better quality than the ones he had seen "four years earlier".
1840s
Herrera peacefully turned over the presidency to the winner of the Federal Elections of 1850, General Mariano Arista. Despite being exiled from Mexico in 1848, Santa Anna would return to the presidency one last time during the 1850s. The 1840s saw the rise of the Daguerreotype. Introduced in 1839, the Daguerreotype was the first publicly announced photographic process and came into widespread use in the 1840s. Numerous events in the 1840s were captured by photography for the first time with the use of the Daguerreotype. A number of daguerrotypes were taken of the occupation of Saltillo during the Mexican–American War, in 1847 by an unknown photographer. These photographs stand as the first ever photos of warfare in history.