CLARKSVILLE, Tenn.—Historic Collinsville in rural Montgomery County will open its annual season this Saturday, April 12, featuring hands-on activities for all ages from 10 a.m. to 4 p.m. as well as tours of the Weakley House Museum. Visitors will experience “On This Day in 1861,” a special theme with activities and programming featuring a glimpse of the everyday life of those at home in a rural Tennessee settlement on the day the Civil War began – April 12, 1861. Guests can become part of the past and interact with living history as they explore the grounds and rooms of the…