I know we haven't finished the movie, but here is some background from In the Time of the Butterflies.
Minerva Mirabal was the first of the sisters to join the revolution. She joined with a young man named Vigilio Morales. They were in love until he was forced to leave the country due to the regime of Leonidas Trujillo.
Trujillo was a gruesome man who killed anyone he needed to get into power. Everyone fell to his whim, and women came to his bedside quite often. That is, until Minerva Mirabal was asked to join him.
At a dinner party Trujillo started touching Minerva on her waste and back, and as a first reaction, she slapped him in the face. She was not arrested, but some type of punishment was about to occur. Her father was taken, and she had to plead with El Jefe (Trujillo), for her father's release.
She went to Trujillo and gambled for a trade. If she were to win, she would be able to attend law school and her father was to be released, but if El Jefe were to win, she would stay there in his house with him as a mistress. She won the deal, and her father was released. He died shortly after, but Minerva was able to attend law school, where she met her future husband/rebel leader, Manolo.
At graduation, Minerva was handed her degree, but not a license to practice law. This truly upset her which is why she spent most of her time after that devoted to the rebels with her sister Mate.
They began getting more people to join them. They were contacting radio stations, churches, men and women. They put up flyers around the city. Shortly after this, Minerva had her first-born child, and soon after, Mate was married. Their lives seemed to be going very well until one day they were both taken to prison. They remained there until they were finally released. After this, their sister Patria joined their cause because she knew it was worth fighting for since her husband was also taken to prison.
They went to churches and held meetings in their houses. Patria let them have weapons stored in the back of her families house. After a while of not being with their husbands, Minerva asked Trujillo if he could arrange it for them to see them. Trujillo granted her wish, and the three sisters went to the prison their husbands stayed at together. After they left they seemed over-joyed until they realized they were being followed by an unmarked car. They soon were pulled over and asked to get out of the car. They were escorted into the jungle, and were surrounded by men with sticks. They realized what was about to happen, and they prepared to die. They were beaten to death and left there. The day of their death, November 25th, is known as National Day Against Violence Towards Women. They will be remembered throughout time by their underground name, which was "The Butterflies". Their legacy was passed on through their children, and their sister Dede, who had been taking care of their children while they were away. 
Dede is still alive today, and continues to tell the story of her sisters. They have all gone down in history. Because they were killed everyone started to riot about their death, and Trujillo was finally taken from power and was assasinated. These sisters were very brave and courageous for what they achieved. It takes a certain kind of person to stand against an entire regime and continuously pursure for their freedom.
Cual fue su parte favorita de la pelicula? Me gusto cuando las hermanas se reunieron para luchar contra Trujillo. 