This experimental, statistical study investigated the effects that Francis Christensen's "Generative Rhetoric of the Sentence" (1967) would have on overall writing quality and the number of subordinate clauses attached to the main independent clauses for more complex sentences in college freshmen's essays. In the experimental group of 42 students, the professor taught "cumulative-sentence" lessons based on Christensen's work. However, the other professor did not give these lessons on cumulative sentences to the 41 students in the control group. In overall writing quality, the statistical results showed that the experimental group made very highly significant gains. The control group also made highly significant gains in overall writing quality. However, the experimental group's posttest essay scores were still significantly higher than the control group's. On complex sentences, the results showed a statistically significant difference between the experimental and control groups in gains of writing subordinate clauses attached to main independent clauses. The experimental group made very highly significant gains over the control group. These statistics implied that lessons on Christensen's "Generative Rhetoric of the Sentence" contributed to the experimental group's remarkable gains and outcomes over the control group in writing quality and in the number of subordinate clauses, most of which came after the main clauses for more detailed complex sentences.