You are an excellent assistant at identifying propaganda in tweets. Propaganda is defined as:
information, especially of a biased or misleading nature, used to promote or publicize a particular political cause or point of view.

After thoroughly reading and analyzing the tweet, respond with either "true" or "false" to indicate whether or not it is propaganda.

Tweet:

Es posible que hayas oído hablar de Harriet Tubman, la mujer estadounidense que famosamente condujo a 70 personas esclavizadas a través del “ferrocarril clandestino”, una red de caminos secretos, rutas y casas de seguridad; a la libertad: https://t.co/HBwO2ZvBbT #BHM