The Welsh Revival in 1904-1906 started with a group of young people thirsty for a deeper knowledge of God and an intimate relationship with Him. Evan Roberts, the prime catalyst used of God in this revival, was virtually unknown when this great work of the Spirit started. His education was limited since he had to leave school at the tender age of 11 to work in the coal mine with his father. Upon his conversion to Christ at the age of 13 he began to pray that God would visit his country of Wales in revival. At the age of 26, he was challenged to be a minister, but in the early stages of his ministry, God interrupted his formal training when revival came to a small church in South Wales.
It began during a Sunday morning meeting after the main service among some of the young people in the congregation of the church in New Quay, South Wales. Young Florrie Evans was just a teenager at the time of a youth meeting in February 1904. Florrie declared publicly that she loved the Lord Jesus with all her heart, and with that, the Holy Spirit descended on the meeting, and the young people reduced to tears. After this meeting, the convicting work of the Spirit of God quickly spread to other young people in the Cardiganshire area. Young people 16-18 years old began traveling with an evangelist, Seth Joshua, who had been praying for revival for some time. His prayer was that the Lord would call a person not from the university or college but the working classes.
Evan Roberts was the answer to his prayer. In the Spring of 1904, Evan experienced a great awareness of God's presence. One night he was awakened from his sleep and was led into deep communion with God for hours. This experience was to continue every evening for the next few months until he went away to a preparatory school for the ministry at Newcastle Emlyn. He was there 2½ weeks before he heard of the Spirit descending on the youth in New Quay. He had to return and receive something himself. In a meeting that Evan was attending, Seth Joshua, the evangelist, challenged the congregation to allow the Spirit of God to “bend” all those that were attending. Evan had been prepared by his evenings of prayer; the Spirit descended on him and filled him. It was a life-changing experience for Evan Roberts. Oswald J. Smith in his book, The Passion for Souls, records Evan Roberts as writing the following words:
For eleven years I had prayed for the Spirit, and this is the way I was led to pray. William Davies, the deacon at the church where he grew up in Christ, said one night in the society: ‘Remember to be faithful. What if the Spirit descended and you were absent? Remember Thomas, Jesus’ disciple, what a loss he had by not being there when Jesus turned up after the resurrection!” “I said to myself: I will have the Spirit’; and through every kind of weather and in spite of difficulties, I went to the meetings. Many times, on seeing other boys with the boats on the tide, I was tempted to turn back and join them. But, no, I said to myself: ‘remember your resolve,’ and on I went. I went faithfully to the meetings for prayer throughout the ten to eleven years I prayed for a Revival. It was the Spirit that moved me thus to think.” At a certain morning meeting which Evan Roberts attended, the evangelist in one of his petitions prayed that the Lord would "bend us." The Spirit seemed to say to Roberts: "That's what you need, to be bent." And thus he describes his experience: "I felt a living force coming into my bosom. This leading of the Spirit grew and grew, and I was almost bursting. I fell on my knees with my arms over the seat in front of me; the tears and perspiration flowed freely. I thought blood was gushing forth." Certain friends approached to wipe his face.
Meanwhile, he was crying out, "O Lord, bend me! Bend me!" Then suddenly the glory broke. Mr. Roberts adds: "After I was bent, a wave of peace came over me, and the audience sang, ‘I hear your welcome voice.' And as they sang I thought about the bending at the Judgment Day, and I was filled with compassion for those that would have to bend on that day, and I wept. 
There is a call for national repentance, prayer, and revival made by Jonathan Cahn at this link:
These experiences of revival are from a series I wrote called: On Fire with the Holy Spirit. It is found on the All Studies page. Scroll down until you come to the series, click on it and the study is called: Revival Comes to the Thirsty Keith Thomas
 http://www.evangelical-times.org/Articles/Aug%2004/Aug04a05.htm  Oswald J. Smith, The Passion for Souls, Welch Publishing Company, Burlington, Canada, Page 42.