Education Commission of the States researched Statewide Longitudinal Data Systems (SLDS) policies in all states, the District of Columbia and Puerto Rico to provide this comprehensive resource. For the purposes of this 50-State Comparison, an SLDS is defined as one with formal connections across two or more of these core agencies. States with at least two of these core agencies in their data systems are designated as having established an SLDS. As such, the data systems that meet this definition might not always be those systems associated with the federal SLDS Grant Program. This resource includes data for all 50 states in 11 categories: (1) Did the state receive a federal SLDS grant?; (2) Years of the grant; (3) How much funding did the state receive for each grant year?; (4) Does the state have a statewide longitudinal data system?; (5) What is the name of the SLDS?; (6) How was the SLDS established?; (7) Established citation; (8) How are the connections structured?; (9) Which of the four core agencies (early learning, K12, postescondary, workforce) are included?; (10) Does the SLDS include a publicly available data dictionary?; and (11) Data dictionary citation.