Edgar Collins, of St Andrew's Close, Shifnal, preyed on two girls who were both under the age of 10 in the late 1990s.
He indecently assaulted both of them on multiple occasions between 1996 and 1999.
Years later, in 2017, he sexually assaulted another girl, who was also under 10.
Collins' crimes came to light recently and he was prosecuted for seven sexual offences against the girls.
He denied all the charges but was found guilty by a jury earlier this year.
One of his victims spoke of being "haunted" by her memories of the abuse he subjected her to, in statements read out at Shrewsbury Crown Court this week.
Prosecutor Mr Benjamin Lawrence referred to impact statements, which mentioned the effects Collins' crimes had had on the victims.
One of those who was abused in the 1990s, now an adult, spoke of the difficulties she faced because of her experiences, including the effects on her relationships with men and her own children.
The court heard that one victim even felt guilty because another girl was abused after her.
Representing Collins, Mr Kevin Jones told the court the defendant was now a "very poorly man" who cared for his wife.
But the judge said it was not his responsibility to deal with "compassionate issues" that might arise from the sentence.
Judge Peter Barrie heard the evidence and told Collins: "The effect on each of [the victims] has been devastating.
"It has affected their relationships, their mental health, their ability to follow a normal and happy life.
"It has fundamentally undermined their sense of security and wellbeing."
For four historic charges of indecent assault against one of the girls, the judge handed down sentences of nine years, four years, three years and three years – all to run concurrently, totalling nine years.
For the two historic offences against the second victim, he was sentenced to three years and 21 months – to concurrent with each other but consecutive to the other offences, equalling 12 years.
And for the 2017 offence of sexual assault, the sentence was two years to run consecutively, which meant he must serve 14 years in total.
Collins will also have to serve an additional year on licence after his sentence is complete.
West Mercia Police's Detective Constable Richard Cowley said: “I would like to thank the victims and their families in this case for their courage, bravery and vigour during our investigation.
"I hope that other victims of sexual offences will take strength and encouragement from this verdict and come forward and report any offences to us, regardless of when they took place.”