I have something of a thick head this morning in the city of brotherly love because last night I celebrated, with an injudicious mixture of champagne, martini and margarita (and nothing but salted snacks to eat) the completion of my project. The journey is not yet over, but when I arrived in Delaware yesterday afternoon I had driven to my 48th American state. 

I drove first yesterday to Gettysburg. After passing, bemused, a uniquely American combination of patriotic song and dance, I went to the Military Park visitor center. I watched the movie about the battle narrated - as seems inevitable now if the subject is grave - by Morgan Freeman. I knew, in general terms, what happened there but I think I began to appreciate the emotional weight it carries for Americans.

The most impressive part of the day was actually the "cyclorama" - an enormous circular painting - enhanced with 3D landscaping and objects in the foreground - by French artist Paul Dominique Phillipoteaux. He and his team of assistants painted it in one year and it was first displayed in Boston in 1884. It has been recently restored at a cost of $13 million and located in the new Gettysburg visitor center in 2008. In all the years since it seems that no-one has devised a better way to present the story of that three day slaughter of Americans by Americans. My only suggestion for improvement is to ask Morgan Freeman to record the narration. It's hard to take anything seriously now in the States without the voice of "God" behind it.

I started on the motor tour of the battlefield in brilliant sunshine. The heat was a little excessive for my top-down tour, but I enjoyed the drive and the conversations with people I met along the way. I offered to photograph a family group in front of the North Carolina monument (sculpted by Mount Rushmore's artist, Gutzon Borglum) where they had been taking pictures of each other. When I asked if they were from NC, the father replied "No, we are from Oregon, but we appreciate what they did."

This neatly illustrates the odd approach that I had already noticed at Vicksburg. The "line" at these Civil War sites is that the soldiers on both sides get credit for the outcome. Of course their bravery in their respective causes is to be respected but, were those soldiers from North Carolina (one of them depicted there is the designer of the Confederate flag) to come back to life, I think they would find the remark strange. History, of course, is constantly rewritten to serve modern purposes - good and bad. Many historical figures would be astonished at the uses to which they are now put. America's national unity is not a bad cause for which to twist reality but like the real Tom Paine I am an admirer of truth for its own sake. He died in disgrace and isolation for that attachment, poor chap and I love his memory all the more for it.

I didn't have time to complete all 16 stations, but I saw six before I set my sat nav to Delaware. For all the reverence for the soldiers who fought at Gettysburg (and Americans are, rightly, great respecters of their fighting men) the truth is the only good thing that happened there was Lincoln's beautiful speech.

It was still too hot for top-down motoring but I have driven so much in the open air that it seemed fitting to arrive that way in my 48th state. I was rather surprised by my own reaction as I pulled into the Delaware Visitor Center (not the usual polite public sector offering, by the way, but a highly-commercial set of restaurants and other businesses with a small kiosk offering the tourism leaflets). In less than two months - and without a break - I have driven to every state on this continent-nation. I planned to do it. It was hardly news to me. Yet I felt enormously excited and pleased - in a little boy on Christmas morning sort of way. I bought a Delaware keychain to add to my trophy collection in a smiley daze and celebrated with a cookie and a Diet Coke before driving on to Philadelphia.

On arrival at my hotel, my excitement spilled over and I told my receptionist and all the staff present that I was here to celebrate the completion of my mission. They responded with true American enthusiasm and helped me get my childish excitement down to more seemly levels, for which I am grateful. Papi, the Colombian bartender (well-trained in London) finished the job later and fixed me the best margarita of my tour. To my surprise then, prim Quaker-founded Pennsylvania wins my personal "All States Margarita Challenge". I was so stoked (as the local expression has it) by then that I didn't even take a photo of the winning drink. Or so I thought until I examined my phone this morning. It seems my habit of documenting the tour is stronger than the alcohol I consumed last night.

Today's mission is to stroll around Philadelphia a little, to see it in the bright sunshine currently hurting my eyes through my hotel window, and then on to Tom Paine's old home in Bordentown. That will complete my New Jersey to New Jersey circuit of America and allow me to pay my personal respects to my hero; the great man whose name I hubristically borrowed for blogging.