The retrieval of contemplation for modern Western Christianity is indebted above all to Thomas Merton (1915-1968), a Trappist monk who was also a scholar, eloquent writer, and committed activist. Merton was the groundbreaker in making the marginal and forgotten contemplative tradition to become known and remembered for the broader public. Through his writings Merton also was instrumental in moving spiritual practices out from where they were cloistered in Catholic monasteries, into a living option for all western Christianity.
Since his untimely death in 1968, a number of streams within contemporary Christianity have continued that work of remembering & retrieving contemplative spiritual practices. Some, like James Finley, had met and studied under Merton and continue his work directly. Others like Thomas Keating (1923-2018) and John Main (1926-1982) founded global organizations (Contemplative Outreach and the World Community for Christian Meditation, evangelizing “centering prayer” and “Christian meditation”, respectively). Richard Rohr created the Center for Action and Contemplation. Some, like Cynthia Bourgeault, travel broadly and deliver lectures or lead retreats. Lauren Artress retrieved the practice of labyrinth walking as a contemplative form and founded the organization Veriditas to disseminate this retrieval globally. The commonalty to all is different forms of active, ongoing practice of contemplative Christian prayer. An excellent brief description of contemplative Christianity, both historical and in contemporary forms, is available at this “Contemplative Christians” link.