Social studies texts often pose a challenge for readers because of their complex linguistics features, which can cause comprehension issues. Drawing upon Systemic Functional Linguistics (SFL), this study examines how authors create cohesive messages and meaning in an 11th-grade U.S. history textbook in relation to the history of diseases. Findings reveal four main cohesive resources: (1) referring words, (2) ellipses, (3) lexical cohesion, and (4) text connectives, are utilized to construct a message that holds together and builds from clause to clause. Consequently, a responsibility is placed on the reader to track the participant(s) while also forcing them to track the events in the rest of the clause. Although the function of cohesive resources helps the writer to express their ideas, it may also impede novice readers, such as emergent bilinguals, from keeping track of all the participants and information. Implications provide ways social studies teachers can take up a role as a language teacher to support comprehension of social studies content and language development.