Odonates are charismatic, ecologically important aquatic insects that have long been recognized as model organisms for the study of sexual character evolution. The Pan-American genus Argia (Zygoptera: Coenagrionidae) contains 110 nominal species, making it the second largest genus in the order Odonata. The Nearctic species are essentially common and can be abundant in and near aquatic habitats, where they are important as both predator and prey in trophic interactions. Monophyly of Coenagrionidae has never been recovered by phylogenetic analysis, and the position of Argia within Coenagrionidae remains uncertain. A robust hypothesis of phylogeny for Argia will improve our knowledge of odonate systematics, as well as increase understanding of the role of sexual selection in speciation. A preliminary phylogeny of the North American species based on cladistic analysis of molecular and morphological data will be presented, the first modern phylogenetic analysis for these species. Variation in secondary sexual characters, as well as future work, will be discussed in light of this preliminary phylogenetic hypothesis.