Engineering for US All (e4usa) is a National Science Foundation-funded first-of-its-kind initiative aimed at making engineering more inclusive and accessible to underrepresented populations. The "for us all" mission of e4usa encompasses both students and teachers. Paramount to the success of e4usa was the construction of professional development (PD) experiences to prepare and support teachers with different levels of engineering teaching experience as they implemented the e4usa yearlong course. The perspectives of nine teachers with varying degrees of engineering teaching experience were examined during two PD opportunities to compare experiences and dynamics between the teachers. Data sources consisting of focus groups and artifacts created during the PD were analyzed using inductive coding and the constant comparative method. The distinct themes that emerged included teachers redefining engineering, growing confidence to teach engineering, benefiting from the PD, receiving support from other teachers, experiencing imposter syndrome, and renewing a passion for engineering education. The results provide implications for how engineering education PD may be developed to allow for reciprocal support and mentoring that supports all teachers regardless of engineering teaching experience. The results also inform future e4usa efforts and aim to change the structure of high school engineering education.