Nationally Known - Locally Active. For more than 100 years, Big Brothers Big Sisters has operated under the belief that every child inherently has the ability to succeed and thrive in life. The nation’s largest donor-supported and volunteer-supported mentoring network, we make meaningful, monitored matches between adult volunteers – our Bigs – and youth – our Littles – ages 6 through 22, in communities across the country. We develop positive relationships that have a direct and lasting effect on the lives of young people – particularly youth from disadvantaged socioeconomic demographics. Our programs operate in 12 counties throughout Northeast Indiana & Southern Michigan.