It's 55 years today that "the moral leader of our nation" delivered his beautiful speech: 'I Have a Dream', at the 1963 'March on Washington for Jobs and Freedom'.

I know that you've probably heard people go on about the greatness of this speech before.

After reading the speech in high school, I remember thinking, sure, it's a good speech.

Yeah, Martin Luther King uses alliteration and metaphors and repetition and imagery and Biblical references - all those rhetorical techniques your teachers tell you to watch out for.

('Anaphora', apparently, is the technical term for repeating a phrase at the beginning of sentences. Who says liberals don't care about good vocab?!)

But what really makes a difference is when you watch it.

The power of words 

When I first did that and saw the moral leader himself on screen, his speech actually sent a shiver down my spine.

King's magnificent, heartfelt, resounding delivery triggered an emotional response in me that words on a page alone just couldn't have.

If a grainy black-and-white movie can do that, just imagine what it must have been like to be there as one of those black or white people on that sunny day in DC.

The first ten minutes are spent laying the groundwork. King lines up references to great American history: from Lincoln's Emancipation Proclamation to Jefferson's promise of "life, liberty and the pursuit of happiness".

Those historical rights were, according to King, a 'promissory note' that America had defaulted upon with regards to its citizens of color.

But he refused to believe "that the bank of justice is bankrupt."

Until that point in the speech, King had been reading from a prepared script.

But then gospel singer Mahalia Jackson, in the crowd that day in DC, cried out: "Tell them about the dream, Martin!"

King then went off script, and, building from previous speeches, told us about his dream (about 12 minutes in on the Youtube clip.

MLK's far away dream to be treated as an equal 

If any of us tried to construct a speech like that by carefully checking off all those rhetorical techniques, we just couldn't do it quite the same.

(Even if, like me, you fancy yourself as a bit of an orator because you've attended Toastmasters a few times!)

Sometimes you hear public figures try to display similar gravitas - but too often they just sound stiff and wooden.

The difference, I think, is that King really did have his heart in that moment and that cause. You see it as he talks about the dream.

When your house has been firebombed in revenge for the success of the Montgomery bus boycott; when you and your brothers have been racially abused and jailed for peaceful protest - then your heart's in it because you know this stuff really matters.

Somehow, though, King doesn't sound angry, frustrated or bitter during that speech.

Stern, sad, forthright, even militant - yes. But also motivated and hopeful and passionate.

You could say King had a right to be angry.

Actually, some other civil rights leaders of the time - like Malcolm X - thought his speech was way too cooperative.

But calling for violent revolution would have distracted from the whole point of the march that day - which was to galvanise mainstream, peaceful support for the Kennedy administration's plans for civil rights legislation.

250,000 people attended the march that day. But remarkably, there wasn't a single arrest related to it.

When we first started Radical Tea Towel back home in the UK, we knew we couldn't be without Dr King and his wise words - in fact, he inspired one of our earliest designs.

Dr King's ongoing wisdom 

You can also see quotations from King all over his monument in DC - I was lucky enough to see that 'stone of hope' on my first visit to DC this summer (pictured earlier in this email).

But there's one person who today has extra special access to King's wisdom in writing.

After finishing his speech, King handed the original typewritten copy to George Raveling, a nearby security guard on the steps of the Lincoln Memorial.

81-year-old George is still with us, and says he'll never sell it - despite supposedly being offered $3m for it.

Presumably, if King really did go off script at the key moment that day, then the original 'I Have a Dream' speech text doesn't actually contain the words 'I have a dream'.

For some things, I guess you just had to be there.