This study examines why Denmark is considered the leader among the Nordic countries and globally when it comes to childcare. In terms of programmatic success, Denmark is a pioneer in nationwide ECEC (early childhood education and care), including social investment, which focuses on learning capabilities and skills of children. The implementation of ECEC nationwide is well organized, and the take-up of ECEC is evenly spread geographically and across social classes. Danish ECEC is also a clear political success, as political parties from the left to the right of the political spectrum, and at central and local levels of government, have supported ECEC, from the 1970s onwards; furthermore, stakeholders have been involved in setting agendas for continued high-quality ECEC as part of Danish family-, childcare- and labour market policy. Linked to the political success, Danish ECEC has also been a clear process success, with incremental reforms by broad-based coalitions, which have been carried out without major obstacles. The Danish system of ECEC has endured over several decades, despite changes at the margin due to challenges, including financial crises. The endurance is likely to continue well into the future, because of the cap on parental own contribution to the costs of ECEC, and because there has been a political decision to have a minimum threshold for quality of care in 2019. Across both sides of the Atlantic, in the EU context and in the US, childcare in Denmark is considered as a poster-child.