The chalkboard was patented in:

Explanation: The chalkboard, also known as the blackboard, began to be widely used in classrooms around 1801. Scottish educator James Pillans is commonly credited with popularizing its classroom use. Before that, students typically wrote on individual slates. The introduction of the chalkboard enabled teachers to write lessons for an entire class at once, making classroom instruction more effective.

Key Facts:

• First widely used in classrooms: Around 1801.
• Popularized by: James Pillans of Scotland.
• Initially made from smooth slate and written on with chalk.
• Modern green and white boards were introduced much later.