Didn't the Church just invent the dogma of the Immaculate Conception in 1854?

“Love the Lord with all your heart, and with all your soul,

and with all your MIND”--Matt 22:37

Question: Regarding the doctrine of the Immaculate Conception, didn't the Church just invent this dogma in 1854?

Firstly, we ought to define what the Immaculate Conception (IC) is.  It is NOT the conception of Jesus in Mary's womb.  We all have heard many women joking that if they're pregnant it must "through the immaculate conception 'cause there's no way I could be pregnant."  
 This is an understandable confusion, especially since the Church always reads the Gospel narrative of the Annunciation, where Mary is told that she will conceive, without marital relations, a son.  Naturally Catholics assume that this is the Immaculate Conception.

However, the IC is the teaching that Mary, from the very first moment of her existence in St. Anne's womb, was free from Original Sin.  That is, she did not lose the supernatural grace that was once part of our humanity but lost through the sin of Adam and Eve.  God created her to be the fitting and perfect vessel for His Divine Son. 

"The dogma is especially fitting when one examines the honor that was given to the Ark of the Covenant. It contained the manna (bread from heaven), stone tablets of the Ten Commandments (the word of God), and the staff of Aaron (an instrument of Israel’s redemption). If this box was created with such honor—to carry a stick, some bread, and stone tablets—how much more should Mary be made a worthy dwelling place for God himself? She is the new Ark of the Covenant because she carried the real bread from heaven, the Word of God, and the instrument of our redemption, Jesus’ body."  source
 
So, did the Church invent this teaching in 1854?

It's true that Pope Pius IX officially defined the doctrine of the IC in 1854.

However, what was solemnly pronounced, declared and defined a certain point of time is not an indication that it only came to be believed at that point.

It has been the "constant teaching" in our house that when the kids come home from school they are to do certain things: hang up their backpacks, put their shoes away, wash their hands, take off their uniforms, eat their snack, finish their chores, practice their piano, etc etc etc.

Despite the fact that they have been doing this every school day for 3-11 years every once in a while we need to have a "family meeting" to pronounce, declare and define exactly who should be doing which job and how it is to be done. (Note: I try to ignore their incredulous looks that say, "What? We're supposed to hang up our backpacks again this year?" or "What? You've never said that we had to take off our uniforms and hang them up!" )

At this council we recall what’s been done in the past, review the current norms and define again exactly what’s the expectation. Sometimes the kids complain that we are “making up new rules”, claiming we’ve “never done it this way before” when in actuality we are just pronouncing, declaring and defining a standard norm of our family.

Thus, the solemn declaration of the doctrine of the Immaculate Conception was not newly formed in 1854. It was a constant belief held and spoken of for many years, sometimes correctly, sometimes incorrectly. 

However, this dogma was ancient, dating back to the times of the apostles. Perhaps in order to alleviate any doubt and to correct any wrong information, God chose 1854 as the time to pronounce, declare and define this belief and practice.

"Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect" - 1 Peter 3:15