This is a broad question, so sorry in advance.
The Iowa caucus and New Hampshire primary are (usually) critical for a presidential hopeful to get the nomination, and Iowa has the extra variable of being a swing state. We see potential presidential candidates spending lots of time in these places to, among other things, schmooze with locals at family diners and barbecues for publicity purposes. I'm curious when this aspect (meeting with locals at stereotypical "American" places/events) became a must for candidates---that need to be seen as a "real" American/Washington outsider/good ol' boy, etc---and how this process expanded or retracted up to the 1992 presidential elections. Also curious what kind of role media has played over the years; also pretty broad but any answer is appreciated.
Well...first of all, the presidential primary is a relatively new thing. Up until the mid twentieth century presidential candidates were chosen at party conventions and primaries, if they existed, were little more than 'beauty contests' that often had no effect on how a state's convention delegates would vote. JFK was the first major party nominee to effectively utilize the presidential primary system to gain the strength necessary to secure the nomination, but it wasn't an easy or surefire road to the nomination until he played up the democratic nature of the primaries (for more on this, check out Robert Caro's latest book). As for New Hampshire, it became a major thing in 1968 when McCarthy's near victory over LBJ cracked open the democratic race for the nomination. After that, New Hampshire became an important factor in Presidential elections. The Iowa caucus came into prominence in 1976 when Jimmy Carter's unexpected victory catapulted him into the national spotlight. Ever since then, these two states have been the centerpiece of a robust primary system.