Here's a nice little essay on the philosophy behind the interior layouts of mid-century residential architecture:



Mid-Century Modern Interiors

When mid-century modern houses were built in the 1950s and 1960s, the most striking feature of their interior was usually their open and flowing floor plan. Living room spaces flowed into the dining room, which flowed into the kitchen. A vaulted ceiling over it all really did make the core of the house one big “great room.” This was, after all, the era of “togetherness.”