The job offer Alex Salmond gave me in 2006 still sits on my mantle.

It's written on a bottle of House of Commons whisky. It was two years after I'd left Westminster and one year before the Scottish election. He was assembling his team for the campaign.

Like the part of the movie where someone gets the band back together, he was reaching out to staff from earlier times - Kevin Pringle for press, Stephen Noon for policy and many others who had a role to play. And then Alex was in Washington DC asking me to come back to help reach out to the business community.

I still remember when he made his pitch. I told him that I believed in him, but with less than a year to go, he was buried in the polls and had no money. Undeterred, he smiled and said: "Yes, but I run faster than anyone else."

He was right. He did. And seven years later, he still does.

For all the things that have been ­written about Scotland's longest-serving first minister, not many have been written by people who used to work for him. And the reason for that, I think, is simple. Most of the people who were working with him 20 years ago are still working with him.

He's that kind of leader. The kind that encourages you to stick around because there are Big Things to do. And when you are with Alex, you know that if you work really hard, big things can happen. And often they do. So as hard as Alex expected his staff to work - as fast as he wanted us to run - we did it knowing that he was always working harder and that the stakes were worth it.

I left Scotland after the 2011 election and moved back home to America. ­Writing now from Washington DC, I have a few reflections to share as he stands down as First Minister. At some point I think he'll write his own story. And I can't wait to read it.

But for now - here is mine.

Alex in London

I met Alex Salmond in London in the winter of 2001. He was in his period between being party leader - four years when he spent most of his days at Westminster, weighing in on debates and, I think, getting much-needed time to think for the political fights to come.

Originally, I moved to London on a six-month secondment to serve as Alex's economic adviser. (He is persuasive - I stayed working for him off and on for 10 years.) He looked at me across the table and asked why I wanted to take a 70% pay cut to work for him. My answer was simple: I wanted to learn from the smartest boss I could find, and people told me that was him.

I remember my first Budget day. I over-prepared, building spreadsheets to calculate the implications for Scotland based on the policies announced. When the Chancellor sat down, I raced down the 39 spiral steps from the SNP whips office to the House of Commons' central lobby to tell Alex my model's output. As I started rambling, he turned over a copy of his order paper with the same numbers. He had already calculated them himself while listening to the speech.

It might surprise people to know what an Anglophile Alex is. But ­professionally, he grew up there - at least 50% of the time. After all, he first walked into ­Westminster when he was 32 years old.

And as happy as he was to get back to his constituency and to his wife, Moira, and their house in Strichen, Alex didn't suffer being in London. He enjoyed it. He would talk to anyone, and plenty of people wanted to talk to him. To have worked for Alex at Westminster meant to get calls from people he had met somewhere or other who he'd promised a tour of the Parliament.

One night we were walking in Kensington to get a late dinner - at Westminster there are few other kinds - as a group of young men in their 20s strolled past, full of alcohol and in high spirits.

They were singing God Save The Queen and one of them had just sung the part about "rebellious Scots to crush" when they passed us in the street. They stopped in their tracks and the lead troubadour did a literal double-take as Scotland's most famous nationalist walked past. Alex simply winked at him and said: "Learn another verse, son."

A different kind of nationalist

While Alex may well be Scotland's most famous nationalist - or perhaps there he is tied with his good friend Sean Connery - he is certainly a different sort of nationalist than what people might imagine.

An example of this came when he went to New York in 2006, before the ­Scottish election. He was attending an event that was going to be filled with American business leaders and celebrities - many dressed in kilts. Alex - the leader of the Scottish National Party - did not own a kilt. Hadn't worn one since he was a boy. But not wanting to disappoint the ­American audience, he got one.

When he became First Minister, you could sense the palpable uncertainty of the civil service - wondering what it meant to have a pro-independence leader of the government. To be fair, they rose to the ­challenge and, I honestly believe, many became animated by and invested in the possibilities that independence could afford.

But in those first months, it must have been a strange thing to go from serving a succession of first ministers who attacked the notion of an independent Scotland to one whose political touchstone was to promote it.

In an early meeting with a speechwriter, a group of us sat around the table as the new First Minister methodically went through the document scratching out references to The Greatness of Scotland. As Alex said: "It is for others to say our nation is great." Or - as I often heard him say it - "I've never said our nation is better than anyone else's, but I refuse to believe it's any worse."

To be sure, Alex would mention Scotland's past glories in speeches, but his new civil servants quickly learned that he was much more interested in what the country was doing or could do than what had happened before.

People often asked me why Alex had an American ­advising him on economic matters. The answer is that I don't think Alex thinks about nationality as much as others do. He wants the best people for the job. He has hired people from America, Canada, Australia - and two of his special advisers are originally from England. He hires whoever he thinks can do the work.

His best friend for many years until he passed away was Bashir Ahmad, a beautiful man and proud Scot who emigrated from Pakistan to Glasgow in his 20s.

To Alex, belief in the future of Scotland is not rooted in ethnicity. While Alex is a student of history, he thinks much more about Scotland's future than its past. And he's not a nationalist who cares at all where someone's ancestors were from. As an American whose grandparents were first-generation immigrants, that always meant a lot to me.

Conviction politician

One of the reasons I worked for Alex for so long - one of the reasons so many of his staff have done so - is that he is an old-school ­conviction politician. As much as his mind is made for strategy and thinking through angles, he does not stray from core principles. And as much as he has a sense of the media moment, he can be incredibly careful about when he uses those moments and when he doesn't.

When I was working with him at Westminster, he handed me a letter as he was exiting a car and asked that I made sure it was on his desk when he got back. It was a letter forwarded from a mother whose son was ­serving in Iraq. This was the early days of the war and the young soldier was writing about the terrible conditions and lack of equipment. He said that they wondered if it was possible to get to Alex Salmond, that they wanted someone to know what was happening.

As a military kid myself, it was moving to imagine these men in harrowing conditions and the simple belief that they needed a champion - not just for themselves, but for the bigger cause of understanding the war - and knew that they had one in Alex. I have no doubt that letters like that one motivated him to continue in his questioning of the Iraq war, becoming one of the principal thorns in Tony Blair's side.

I saw that same conviction when he was first minister each time he confronted big challenges. During the Megrahi compassionate release process, for example, he was ­decidedly calm. Alex is a man who believes in principles and believes in process. He also trusts his team - his Cabinet and his civil servants - to do what is right. And then he lets the chips fall where they may.

In the end, divisive as the initial ruling was, there was a reason that I think polls quickly showed the public's faith in the integrity of the process. They could see people, including at every level of government, doing their best to follow the rules. In a cynical age, that says a lot.

And as affable as Alex can be one to one, he does not shy from ­telling people what he thinks. Once, in America, a prominent Republican politician was talking about how much he loved Scotland, but he didn't understand how the home of "the great capitalist Adam Smith" (as the Republican put it) could have ended up "so darn liberal". Alex smiled. "Well, Senator," he said. "I think you'll find that in Scotland, we read the whole book."

The man

Some politicians see campaigning as ­drudgery. They want to think big thoughts and give big speeches, but they don't have much heart for going to where people live and knocking on doors. Put simply, they want to do politics wholesale, not retail.

But not Alex. One of his most marked characteristics is he likes people - not just the idea of them, but actually meeting them. It's one of the reasons his schedule is always behind, because Alex will almost never be the one to end a conversation. For this reason, going to dinner with him in public is difficult, as is walking down the street.

My parents met Alex years ago when he gave a speech at the University of Virginia. Afterwards, I was rushing around trying to make sure journalists and constitutional scholars had a chance to meet him. And I kept having to pull him away from my parents - quiet, Midwestern, and not at all political - as my father asked him questions about Scotland and how he was finding America. He would have stayed there all ­afternoon - just as happy to talk to my dad, the retired naval officer with no vote in Scotland as the VIPs who waited to welcome him.

Back in Scotland, Alex gave me a bottle of whisky, this time from the Scottish Parliament, to send to my father. He pulled out a piece of stationery and wrote a note, remembering not only my father's profession but also greeting him with the title no-one had addressed him with in years:

Dear Commander Erickson,

I thought you might like one of ­Scotland's most famous products.

Many thanks for allowing your daughter to stir up revolution on this side of the water.

Yours for Scotland, Alex Salmond

There are other stories people can tell, or perhaps Alex will one day tell himself. About how much he loves golf. (When he learned I'd never played, he took me right then in the middle of the day - both of us in business suits - to the nearest course and demanded that I practice my swing.)

About life in Strichen (after some ducks decided to make their home in the stream behind Moira's garden, Alex encouraged us to stop ordering duck for a time at late-night Westminster dinners in solidarity). About his uncanny knack for betting on races. (He gave two of his staffers tips for Musselburgh before their joint stag party and their £30 bet netted them £1600 in winnings.)

For all the talk about Alex being a "transformational politician", there is one thing I'm sure of: that he was shaped by Scotland as much as he eventually shaped it. That being the son of a hard-working civil servant imbued him with a sense of public service.

That as much as he could have stayed in the private sector and risen to the top of the UK establishment ranks - and frankly been an incredibly wealthy man - he was much more interested in giving a seat at the table to the men and women he represented in the northeast of Scotland than having the seat at the table just for himself.

That his belief in his country was fundamentally shaped by his belief in people - and key to that, his belief includes the people who choose to come to Scotland as much as those who were born there.

Several people have asked me what Alex thinks about the independence referendum result - how he feels coming so close to seeing his dream ­realised. To be honest, I haven't asked him, and I wouldn't presume to guess. But I do know this: he looked incredibly calm when he said on the night of the referendum, "we're now in the hands of the Scottish people and there's no safer place to be". He trusts people. And I've never once heard him blame the electorate for any of their votes.

Alex was without question a transformational politician. But the thing is, he tapped into something that was there - a quiet confidence and sense of common purpose. And what the world saw on September 18 was democracy in action quite unlike it had ever been before.

Some 85% of the electorate turned up to have their say on something UK politicians had been saying for a generation was a sideshow, a distraction. Almost half the country voted Yes. And just over half the country voted No.

But this is the thing about having a transformational leader in office. In this process - in the conversation and in the ballot booth - Scotland itself was transformed.

Alex used to tell me never to make short-term predictions. But ­something tells me that largely because of the patience and persistence of Alex Salmond and his team - and more importantly because of the movement of people that now has a voice and is not likely to retreat into the shadows - the question of Scotland's future will once again be in the hands of the Scottish people.

And, again, I'm sure Alex would say there is no place safer to be.