The New World sparrows (Passerellidae) are a large and diverse group of songbirds that have been the subject of many studies on ecology, behavior, and evolutionary relationships. Here, we studied two clades of sparrows (Aimophila, Peucaea) to examine the evolution of behavioral, morphological, and ecological traits in a phylogenetic framework. Specifically, we inferred phylogenetic relationships in these clades, conducted ancestral state reconstructions, and asked whether patterns of trait evolution extend more broadly to New World Sparrows. Our phylogenetic analyses recovered relationships that support recent taxonomic revisions and improve our understanding of relationships among species within the genera Aimophila and Peucaea. Analyses of trait evolution revealed that behavioral traits exhibit stronger phylogenetic signal than morphological traits within these genera and more broadly across New World Sparrows. The most highly conserved derived trait was the presence and structure of song duets. Song structure also tended to be maintained within clades once evolved, and there appears to be a trade-off between song complexity and plumage patterning. Habitat covaries with some traits in our focal clades but is not the sole evolutionary driver, because even within lineages that share the same habitat type, species exhibit variation in nesting, plumage patterning, song complexity, and duetting behavior. Our study uncovers interesting patterns of phenotypic evolution in New World Sparrows and highlights the strong phylogenetic signal of behavior in this group. More broadly, our study reinforces the value of examining behavioral, morphological, and ecological traits in combination with phylogenies to reveal patterns of evolution.