The Impressionist movement developed in Paris in the 1860s in response to the conservative Salon de Paris. Artists like Monet, Renoir, Pissarro, and Sisley rejected the Salon's strict rules and instead aimed to capture fleeting moments and sensory impressions of light through loose brushwork and painting outdoors. This was inspired by early innovators like Manet, whose 1863 painting Le déjeuner sur l'herbe scandalized viewers with its casual portrayal of nude women but influenced later Impressionists. The movement spread their techniques of portraying transient effects of light and atmosphere through Europe and the United States.