What is your source for that?
In Acts and in the Epistles we see plenty of hierarchy. The dietary restrictions are lifted, for example, by the Jerusalem council inspired by St. Peter's vision -- no input form the "congregation" was sought. St. Paul likewise sounds quite autocratic, for example, in his letters to Corinthians whom he reminds of his power as Apostle of Christ and threatens with his rod:
16 Wherefore I beseech you, be ye followers of me, as I also am of Christ. 17 For this cause have I sent to you Timothy, who is my dearest son and faithful in the Lord; who will put you in mind of my ways, which are in Christ Jesus; as I teach every where in every church. 18 As if I would not come to you, so some are puffed up. 19 But I will come to you shortly, if the Lord will: and will know, not the speech of them that are puffed up, but the power. 20 For the kingdom of God is not in speech, but in power. 21 What will you? shall I come to you with a rod; or in charity, and in the spirit of meekness?(1 Cor 4)
It would stand to reason that missionary activity somewhat preceded the episcopal duties, as one needs to have converts before there is a church for him to oversee. However, St. Ignatius of Antioch, active in late 1c, possibly early 2c, leaves no doubt as to the hierarchical nature of the Church:
Chapter 8. Let nothing be done without the bishop.
See that you all follow the bishop, even as Jesus Christ does the Father, and the presbytery as you would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop. Let that be deemed a proper Eucharist, which is [administered] either by the bishop, or by one to whom he has entrusted it. Wherever the bishop shall appear, there let the multitude [of the people] also be; even as, wherever Jesus Christ is, there is the Catholic Church. It is not lawful without the bishop either to baptize or to celebrate a love-feast; but whatsoever he shall approve of, that is also pleasing to God, so that everything that is done may be secure and valid.
Chapter 9. Honour the bishop.
Moreover, it is in accordance with reason that we should return to soberness [of conduct], and, while yet we have opportunity, exercise repentance towards God. It is well to reverence both God and the bishop. He who honours the bishop has been honoured by God; he who does anything without the knowledge of the bishop, does [in reality] serve the devil. Let all things, then, abound to you through grace, for you are worthy. You have refreshed me in all things, and Jesus Christ [shall refresh] you. You have loved me when absent as well as when present. May God recompense you, for whose sake, while you endure all things, you shall attain unto Him.
annalex-"What is your source for that?"
My understanding is that wmfights (and I) believe that the church was ruled by bishops who, on occasion, would come together to resolve disputes. While there appears to be some order, no one voted for leadership. Contrary to what is often portray, the first Council in Jerusalem as recorded in Acts was not lead by Peter but by James. I believe you'll find the Orthodox don't cotton to a "one infallible" Pope.