The 2nd World Congress on Undergraduate Research, held at the University of Oldenburg, Germany, May 23-25, 2019, aimed to foster global dialogue across diverse research disciplines. It brought together exceptional undergraduate researchers to collaborate on pressing international challenges of the 21st century. The event featured six interdisciplinary themes that allowed students to present and discuss their research in lectures and poster sessions, and was framed by a two-day social program. In total, 467 participants from 35 countries and 98 universities presented their work. More than 60 students from low-income countries benefited from travel grants and the "beds for brains" program which organized private accommodations. This article outlines the concepts, organizational challenges, and evaluation results of the congress.