June 2010 (approximate date). The first DevOpsDays in the United States, held in Mountain View, California. The event brought the conference series to the US practitioner community and produced the cams-framework — the first systematic attempt to define what DevOps actually means.
CAMS. john-willis and damon-edwards coined CAMS at this conference: Culture, Automation, Measurement, Sharing. The framework addressed a pressing definitional problem: DevOps had a name and a growing community, but people disagreed about whether it was a set of tools, a cultural movement, a set of practices, or something else. CAMS answered: it's all of these, organized under four dimensions.
The CAMS framework was later extended to CALMS with the addition of Lean (reflecting the lean manufacturing roots of much DevOps thinking), though CAMS remained the original formulation.
Context. The devops-cafe-podcast, co-hosted by Willis and Edwards, had launched in 2010 and was already building a US audience for DevOps ideas. The Mountain View event gave that audience a physical gathering point. The US DevOps community was concentrated in the Bay Area at this point — web-native companies, cloud infrastructure companies, and technology-forward startups.
The exact date is approximate; the event was held in June 2010.