In 2019, 851,508 persons were apprehended at the Southwestern US border without lawful immigration status in the US; of whom 473,682 were part of a family unit, and 76,020 were classified as unaccompanied children (UC). UC are those entering the US under the age of 18 without a parent/legal guardian available to care for them. Recent research on unaccompanied children in the US has focused on educational outcomes, trauma, family separation at the border, and resiliency. However, more research is needed around this population given their unique vulnerabilities, the current unreceptive political climate in the US, and the fact that 2019 has had the highest arrival numbers yet. This dissertation draws on administrative data to provide information that can improve the services that social service agencies are delivering, to highlight areas of future research, and to recommend specific tools for data collection. I aim to advance three areas of research related to the human rights violations and social exclusions experienced by unaccompanied immigrant and refugee children in the US, as well as best practices used by service providers. The three areas are: (1) to understand the systems level facilitators and barriers to adjustment for UC, (2) to understand the challenges to formal education for UC, and the strategies that service providers are using to overcome these challenges, and (3) to examine the predictors of self-sufficiency for unaccompanied immigrants leaving foster care. The findings presented in this dissertation have multiple implications for policy, practice, research, and social work education. The qualitative studies provide a groundwork from which we can conduct more research in order to evaluate the effectiveness of the promising practices described, and advocate to increase funding and service availability. Through a greater understanding of the benefits and challenges to education for UC in foster care, we can build more inclusive and welcoming school environments, ultimately leading to higher educational attainment. Understanding the predictors of self-sufficiency can help caseworkers to better create service plans, and help agencies to advocate for funding of supplementary programming. Altogether, it is my hope that this knowledge can contribute to supports that help UC to be happier, thrive in school, and become productive members of our community.