If you want a career in history but don't have time to enroll in a full time bachelor's degree program at a college or university, you still have several options. Both of these options allow you to work full time and fulfill your family obligations while also attending school. A good way to start is by earning a social sciences degree with an emphasis in history. This will make the eventual transfer to a four year college easier and introduce you to the field gently.
The first way to go about breaking into the field of history with an associate's degree is to look for night classes at a local community college. Community colleges cater to working adults and often offer degree programs that take tight schedules into consideration. Some allow students to take fewer classes per term over a longer period of time. These programs will teach you the basics of social sciences and history, but they also perform another great function. They allow you to meet others who share your interests and bounce your ideas off of them. Professors at community colleges often work in the field as well and have realistic views of what it takes to be a historian.
The other option, and the one that tends to work best for those in real time crunches, it to take online courses. There are many degree programs in this field that are offered either partially or completely online. Some allow students to enroll part time and complete courses slowly. Others are organized in a more regimented way and require that students complete a certain number of courses per semester in order to graduate. Which option you choose is completely up to you. There are advantages and disadvantages to both, but in the end they both can help you break into the field with an associate's degree.