[This paper is part of the Focused Collection on Instructional labs: Improving traditions and new directions.] This paper presents a historical analysis of the development, implementation, research, and assessment of an evidence-based introductory algebra-based physics course. The course is laboratory based and taught with an inquiry-based pedagogy. The course has remained unique and has been taught consistently for over 20 years. It is taught predominantly to health science majors and is completely laboratory based without a lecture and without a required text. Students learn by working through a guided inquiry manual in groups, doing experiments to explore the nature of the world around them. They develop both quantitative and qualitative models based on their experiments. The focus is as much on critical thinking, modeling, and thinking like a scientist, as on physics content. I discuss the course throughout the years, presented in the context of the field of physics education research historically and the state of our department locally. The results of multiple forms of assessment are presented chronologically. The assessments were designed to answer research questions about the students' conceptual understanding and thinking skills, the effects of class size expansion, and questions about learning assistants' pedagogical content knowledge. One finding was that the conceptual understanding of students in the inquiry-based course was significantly higher than students taught traditionally but not significantly different from students taught by other research-informed pedagogies. However, we found that students taught in the inquiry-based format showed more evidence of the application of thinking skills as assessed by our thinking skills rubric in free-response exam problems. We have demonstrated that it is possible to expand a laboratory-based, inquiry-based physics course from sections of 24 students to sections of 60 students with the help of learning assistants and we have developed and validated a set of questions that can be used to measure learning assistants' pedagogical content knowledge or for learning assistant training purposes.