Question: In what year was the first Impressionist art exhibition held?
About the article "Claude Monet", section "Impressionism".

Candidate passages:
The Grafton Galleries, often referred to as the Grafton Gallery, was an art gallery in Mayfair, London.
The French art dealer Paul Durand-Ruel showed the first major exhibition in Britain of Impressionist paintings there in 1905.
Roger Fry's two famous exhibitions of Post-Impressionist works in 1910 and 1912 were both held at the gallery. 
Macintyre Art Advisory are a London based art consultancy who were instrumental in organising the Orientalist and Impressionist Exhibition 2007, Doha.
Held at the Four Seasons Hotel it was the first event of its kind for the region and made works by Rudolf Ernst, John Singer Sargent, Edwin Lord Weeks, James Tissot and Pablo Picasso available for public viewing. 
Monet and Impressionism.
First "Impressionist" exhibition.
From the late 1860s, Monet and other like-minded artists met with rejection from the conservative Académie des Beaux-Arts which held its annual exhibition at the Salon de Paris.
During the latter part of 1873, Monet, Pierre-Auguste Renoir, Camille Pissarro, and Alfred Sisley organized the Société anonyme des artistes peintres, sculpteurs et graveurs (Cooperative and Anonymous Association of Painters, Sculptors, and Engravers) to exhibit their artworks independently.
At their first exhibition, held in April 1874, Monet exhibited the work that was to give the group its lasting name.
"Impression, Sunrise" was painted in 1872, depicting a Le Havre port landscape.
From the painting's title the art critic Louis Leroy, in his review, "L'Exposition des Impressionnistes," which appeared in Le Charivari, coined the term "Impressionism".
It was intended as disparagement but the Impressionists appropriated the term for themselves.  
Stanislas Victor Edouard Lépine (October 23, 1835 – September 29, 1892) was a French painter who specialized in landscapes, especially views of the Seine.Lépine was born in Caen.
An important influence in his artistic formation was Corot, whom he met in Normandie in 1859, becoming his student the following year.
Lépine's favorite subject was the Seine, which he was to paint in all its aspects for the rest of his life.
He participated in the first Impressionist exhibition, held at Nadar's in 1874, although he is generally not considered an Impressionist.
His paintings are placid in mood and are usually small in scale.
Lépine was awarded the First Prize medal at the Exposition of 1889.
He died suddenly in Paris in 1892. 
The Wallraf-Richartz collection includes the work of Impressionist painter, Berthe Morisot, which was painted in 1881, and is entitled, "Child among staked roses" or "Kind zwischen Stockrosen".
In 1864, paintings by Morisot began to be admitted for exhibition in the highly esteemed Salon de Paris.
Sponsored by the government and judged by academicians, the Salon is the annual juried exhibition of the best new paintings and sculptures, the official art exhibition of the Académie des beaux-arts in Paris.
Her work continued to be selected for exhibition in the salon for ten years before, in 1874, she joined the "rejected" Impressionists in the first of their own exhibitions.
Organized by Cézanne, Degas, Monet, Morisot, Pissarro, Renoir, and Sisley, it was held at the studio of the photographer, Nadar.