Text4baby is the first free national health text messaging service in the United States that aims to provide timely information to pregnant women and new mothers to help them improve their health and the health of their babies. Here we describe the development of the text messages and the large public-private partnership that led to the national launch of the service in 2010. Promotion at the local, state, and national levels produced rapid uptake across the United States. More than 320,000 people enrolled with text4baby between February 2010 and March 2012. Further evaluations of the effectiveness of the service are ongoing; however, important lessons can be learned from its development and uptake.