Urbanization can significantly alter species composition by reducing native species populations, increasing the prevalence of non-native or disturbance tolerant species, and contributing to biotic homogenization- the process where an ecological community becomes increasingly similar in species composition over time. Urban effects are often assessed using spatial urban to rural gradients with few studies examining impacts across a temporal scale. Using herbarium records, we examined how urbanization has influenced plant communities over time. Our study focused on 6 Northeastern United States urban centers and compared herbarium records from pre and post urbanization time periods. Measures of ecosystem integrity (Coefficients of Conservatism values) show a decline in high value species as well as a shift in native and non-native species, while maintaining overall species richness, reflecting a shift towards a more generalized and widespread taxa. We are continuing to examine whether those shifts are evidence of biotic homogenization with urban flora becoming compositionally similar across each city over time. Our findings aim to further push the need for research in this area while also providing urban planners with evidence that emphasizes the importance of incorporating native species and maintaining high quality habitats when designing urban green spaces and shaping environmental legislation.