What impact did the oil crises of 1973 and 1979 have on the North American economy/society?

One major short-term impact was that these oil crises contributed to significant inflation that lasted more or less throughout the 1970s. Rising fuel prices tend to affect all sectors of the economy, causing increased production and distribution costs that are passed on consumers who are already paying more for fuel for their personal and household needs. This occurred at a time when the economy was already sluggish; indeed it contributed to the economic slowdown. 

Another impact in the short term was that the United States engaged in serious diplomatic efforts to end the conflict between Israel and its Arab neighbors. American support for the Israelis had been a major reason why the OPEC nations implemented the embargo in the first place, and while the efforts obviously failed to bring about lasting peace in the region, some diplomatic inroads were made, especially by Presidents Nixon and Carter. 

A longer-term impact was that the crisis raised awareness of the need for fuel conservation on the one hand, and what would become known as "energy independence" on the other. To achieve the first goal, the United States government implemented fuel efficiency regulations on automobile manufacturers and (temporarily, as it turned out) imposed a national maximum speed limit of 55 MPH. Market forces also contributed to the rise of fuel efficient cars, as consumers demanded cars that needed less fuel. To achieve the second, the United States began to pursue some alternative energy measures, but mainly to locate new sources of oil, and, most significantly for future generations, to step up its diplomatic and later military presence in the Middle East.