Problem: Stephen Arthur Stills (born January 3, 1945) is an American singer, songwriter, and multi-instrumentalist best known for his work with Buffalo Springfield and Crosby, Stills, Nash & Young. Beginning his professional career with Buffalo Springfield, he composed one of their few hits "For What It's Worth," which became one of the most recognizable songs of the 1960s. Other notable songs he contributed to the band were "Sit Down, I Think I Love You

Stills, Furay, and Young reunited in Los Angeles and formed the core of Buffalo Springfield. Legend has it that Stills and Furay recognized Young's converted hearse on the streets of LA and flagged him down, a meeting described in a recent solo track "Round the Bend." The band would release three albums: Buffalo Springfield, Buffalo Springfield Again, and Last Time Around, and enjoy only one hit single, the Stills-penned "For What It's Worth" before disbanding. A Stills song from their debut album, "Sit Down, I Think I Love You," was a minor hit for the Mojo Men in 1967. During the disintegration of Buffalo Springfield, Stills played on the Super Session album with Al Kooper and joined up with David Crosby, who had recently been ejected from the Byrds in the autumn of 1967. At a party in Laurel Canyon, Crosby was introduced to Graham Nash by a mutual friend, Cass Elliot (formerly of the Mamas and the Papas), and Nash found himself soon joining in singing with Crosby and Stills. Renditions of the latter's "You Don't Have to Cry," led to the formation of Crosby, Stills & Nash. Several of Stills's songs, including "Suite: Judy Blue Eyes" and "You Don't Have To Cry" on the debut album were inspired by his on-again-off-again relationship with singer Judy Collins. In a 1971 interview in Rolling Stone the interviewer noted, "so many of your songs seem to be about Judy Collins." Stills replied, "Well, there are three things men can do with women: love them, suffer for them, or turn them into literature. I've had my share of success and failure at all three." The cover photo pictured on the debut was taken on the back porch of a house in West Hollywood, which was torn down the next day. Wanting to be able to tour and needing additional musicians, the band invited Neil Young to join them for their subsequent tour and second album to make the group the quartet Crosby Stills Nash & Young. Having played at the Monterey Pop Festival with Buffalo Springfield, and both Woodstock and Altamont with CSNY, Stills performed at all three of the iconic U.S. rock festivals of the 1960s.

did he sing with anybody else?

Answer with quotes: Al Kooper

Background: Rowan & Martin's Laugh-In (often simply referred to as Laugh-In) is an American sketch comedy television program that ran for 140 episodes from January 22, 1968, to March 12, 1973, on the NBC television network. It was hosted by comedians Dan Rowan and Dick Martin. Laugh-In originally aired as a one-time special on September 9, 1967, and was such a success that it was brought back as a series, replacing The Man from U.N.C.L.E. on Mondays at 8 pm (ET). The title of the show was a play on the "love-ins" or "be-ins" of the 1960s hippie culture, terms that were, in turn, derived from "sit-ins", common in protests associated with civil rights and antiwar demonstrations of the time.
Context: The first season featured some of the first music videos seen on network TV, with cast members appearing in films set to the music of the Nitty Gritty Dirt Band, the Bee Gees, the Temptations, the Strawberry Alarm Clock, and the First Edition. During the September 16, 1968, episode, Richard Nixon, running for president, appeared for a few seconds with a disbelieving vocal inflection, asking "Sock it to me?" Nixon was not doused or assaulted. An invitation was extended to Nixon's opponent, Vice President Hubert Humphrey, but he declined. According to George Schlatter, the show's creator, "Humphrey later said that not doing it may have cost him the election", and "[Nixon] said the rest of his life that appearing on Laugh-In is what got him elected. And I believe that. And I've had to live with that." In an episode of the ill-fated 1977 revival, a Nixon impersonator says "I invited the American people to sock-it-to-me.... you can stop now". On multiple occasions, producer George Schlatter attempted to get William F. Buckley Jr. to appear on the show, only to be refused each time until he suddenly agreed to an appearance. In the episode that aired December 28, 1970, Buckley appeared in an unusual sit-down segment (portions of which were scattered throughout the episode) flanked by Rowan and Martin and fielding questions from the cast (which included Lily Tomlin doing her Fast Talker shtick) and giving humorous answers to each. Near the end, when Rowan asked Buckley why he finally agreed to appear on the show, Buckley explained that Schlatter had written him "an irresistable letter" in which he promised to fly Buckley out to California "in an airplane with two right wings". At the end, Rowan thanked him for appearing, noting that "you can't be that smart without having a sense of humor, and you have a delightful one".
Question: What else happened that was memorable?
Answer: During the September 16, 1968, episode, Richard Nixon, running for president, appeared for a few seconds with a disbelieving vocal inflection, asking "Sock it to me?"

Question:
Indigenous languages of the Americas are spoken by indigenous peoples from Alaska and Greenland to the southern tip of South America, encompassing the land masses that constitute the Americas. These indigenous languages consist of dozens of distinct language families, as well as many language isolates and unclassified languages. Many proposals to group these into higher-level families have been made, such as Joseph Greenberg's Amerind hypothesis. This scheme is rejected by nearly all specialists, due to the fact that some of the languages differ too significantly to draw any connections between them.
Although both North and Central America are very diverse areas, South America has a linguistic diversity rivalled by only a few other places in the world with approximately 350 languages still spoken and an estimated 1,500 languages at first European contact. The situation of language documentation and classification into genetic families is not as advanced as in North America (which is relatively well studied in many areas). Kaufman (1994: 46) gives the following appraisal: Since the mid 1950s, the amount of published material on SA [South America] has been gradually growing, but even so, the number of researchers is far smaller than the growing number of linguistic communities whose speech should be documented. Given the current employment opportunities, it is not likely that the number of specialists in SA Indian languages will increase fast enough to document most of the surviving SA languages before they go out of use, as most of them unavoidably will. More work languishes in personal files than is published, but this is a standard problem. It is fair to say that SA and New Guinea are linguistically the poorest documented parts of the world. However, in the early 1960s fairly systematic efforts were launched in Papua New Guinea, and that area - much smaller than SA, to be sure - is in general much better documented than any part of indigenous SA of comparable size. As a result, many relationships between languages and language families have not been determined and some of those relationships that have been proposed are on somewhat shaky ground. The list of language families, isolates, and unclassified languages below is a rather conservative one based on Campbell (1997). Many of the proposed (and often speculative) groupings of families can be seen in Campbell (1997), Gordon (2005), Kaufman (1990, 1994), Key (1979), Loukotka (1968), and in the Language stock proposals section below.
Answer this question using a quote from the text above:

What were some of the popular languages being spoken?

Answer:
many relationships between languages and language families have not been determined