He married well, taking wives from the village of Tola'ltu just southeast of Duwamish Head on Elliott Bay (now part of West Seattle). His first wife died after bearing a daughter. A second wife bore him sons and daughters. The most famous of his children was Princess Angeline. After the death of one of his sons, he sought and received baptism in the Roman Catholic Church, probably in 1848 near Olympia, Washington. His children were also baptized and raised in the faith, and his conversion marked his emergence as a leader seeking cooperation with incoming American settlers.

Chief Seattle gave a speech in January 1854 that was reported by Dr. Henry A. Smith in the Seattle Sunday Star in 1887. It is most usually called Seattle's Reply since it was a response to a speech by Territorial Governor Isaac I. Stevens. While there is no question that Chief Seattle gave a speech on this occasion, the accuracy of Smith's account is doubtful. Even more dubious are the later accounts that derive from Smith's. [3], (Speidel, 1978, 169-70)

While Smith is known to have been present to hear the speech, he did not speak Chief Seattle's native Lushootseed, and there is some question as to how much was translated even into Chinook at the time. According to the National Archives and Records Administration, "The absence of any contemporary evidence...create[s] grave doubts about the accuracy of the reminiscences of Dr. Smith in 1887, some thirty-two years after the alleged episode. Thus it is impossible...to either confirm or deny the validity of this...message." Certainly, the rhetorical flourishes in Smith's version are his own, not Chief Seattle's. Many of the concepts and words present in Smith's version would be difficult to convey in Chinook, and it seems clear that Smith's rendition may capture the style of Seattle's speech, rather than its specific contents. While the content of the speech is in question, contemporary witnesses agree that it was about half an hour in length, and that, throughout, Chief Seattle, a tall man, had one hand on the head of the diminutive Governor Stevens.

William Arrowsmith edited a second version of the speech into contemporary language in the 1960s. The speech became famous again when a third version began to circulate in the 1980s. Joseph Campbell, with Bill Moyers, (1988, pp. 32-34) [4] quoted Chief Seattle speech. The newest version bears little resemblance to the old one. It is the work of Ted Perry, a scriptwriter for a 1972 film about ecology called Home. This version casts Chief Seattle as an early ecological visionary, speaking of the insights of his people into the workings of nature. It led to his becoming a role model of the environmental movement (rightfully or not). A shortened rendering of the third version is also circulating.